Remove chai and assert from global window

It has caused accidents where 'assert' is used in prod code without an
import, and typescript does not notice the issue. Examples:

https://gerrit-review.googlesource.com/c/gerrit/+/343916
https://gerrit-review.googlesource.com/c/gerrit/+/343475

Removal is in common-test-setup.ts, package.json, and BUILD. All other
ts/js files are just adding the import from @open-wc/testing.

Release-Notes: skip
Change-Id: Ie38c0a52d6a0f8f7f1468e2e8fc9b721d4aef734
diff --git a/polygerrit-ui/BUILD b/polygerrit-ui/BUILD
index 4618a14..0ac2ab4 100644
--- a/polygerrit-ui/BUILD
+++ b/polygerrit-ui/BUILD
@@ -40,7 +40,6 @@
     srcs = ["@ui_dev_npm//:node_modules/karma/bin/karma"],
     data = [
         "@ui_dev_npm//@open-wc/karma-esm",
-        "@ui_dev_npm//chai",
         "@ui_dev_npm//karma-chrome-launcher",
         "@ui_dev_npm//karma-mocha",
         "@ui_dev_npm//karma-mocha-reporter",
diff --git a/polygerrit-ui/app/elements/admin/gr-access-section/gr-access-section_test.ts b/polygerrit-ui/app/elements/admin/gr-access-section/gr-access-section_test.ts
index 1c6a013..36a568b 100644
--- a/polygerrit-ui/app/elements/admin/gr-access-section/gr-access-section_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-access-section/gr-access-section_test.ts
@@ -13,7 +13,7 @@
 import {GitRef} from '../../../types/common';
 import {queryAndAssert} from '../../../utils/common-util';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-access-section tests', () => {
   let element: GrAccessSection;
diff --git a/polygerrit-ui/app/elements/admin/gr-admin-group-list/gr-admin-group-list_test.ts b/polygerrit-ui/app/elements/admin/gr-admin-group-list/gr-admin-group-list_test.ts
index 331c2c7..fc3b3d7 100644
--- a/polygerrit-ui/app/elements/admin/gr-admin-group-list/gr-admin-group-list_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-admin-group-list/gr-admin-group-list_test.ts
@@ -19,7 +19,7 @@
 import {GrDialog} from '../../shared/gr-dialog/gr-dialog';
 import {GrOverlay} from '../../shared/gr-overlay/gr-overlay';
 import {SHOWN_ITEMS_COUNT} from '../../../constants/constants';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 function createGroup(name: string, counter: number) {
   return {
diff --git a/polygerrit-ui/app/elements/admin/gr-admin-view/gr-admin-view_test.ts b/polygerrit-ui/app/elements/admin/gr-admin-view/gr-admin-view_test.ts
index 158679c..5f2cb26 100644
--- a/polygerrit-ui/app/elements/admin/gr-admin-view/gr-admin-view_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-admin-view/gr-admin-view_test.ts
@@ -21,7 +21,7 @@
 import {GrDropdownList} from '../../shared/gr-dropdown-list/gr-dropdown-list';
 import {GrGroup} from '../gr-group/gr-group';
 import {GroupDetailView, RepoDetailView} from '../../../utils/router-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 function createAdminCapabilities() {
   return {
diff --git a/polygerrit-ui/app/elements/admin/gr-confirm-delete-item-dialog/gr-confirm-delete-item-dialog_test.ts b/polygerrit-ui/app/elements/admin/gr-confirm-delete-item-dialog/gr-confirm-delete-item-dialog_test.ts
index 982e42a..fbf03c0 100644
--- a/polygerrit-ui/app/elements/admin/gr-confirm-delete-item-dialog/gr-confirm-delete-item-dialog_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-confirm-delete-item-dialog/gr-confirm-delete-item-dialog_test.ts
@@ -8,7 +8,7 @@
 import {GrConfirmDeleteItemDialog} from './gr-confirm-delete-item-dialog';
 import {queryAndAssert} from '../../../test/test-utils';
 import {GrDialog} from '../../shared/gr-dialog/gr-dialog';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-confirm-delete-item-dialog tests', () => {
   let element: GrConfirmDeleteItemDialog;
diff --git a/polygerrit-ui/app/elements/admin/gr-create-change-dialog/gr-create-change-dialog_test.ts b/polygerrit-ui/app/elements/admin/gr-create-change-dialog/gr-create-change-dialog_test.ts
index b885279..d1fc6b1 100644
--- a/polygerrit-ui/app/elements/admin/gr-create-change-dialog/gr-create-change-dialog_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-create-change-dialog/gr-create-change-dialog_test.ts
@@ -11,7 +11,7 @@
 import {createChange} from '../../../test/test-data-generators';
 import {queryAndAssert, stubRestApi} from '../../../test/test-utils';
 import {IronAutogrowTextareaElement} from '@polymer/iron-autogrow-textarea/iron-autogrow-textarea';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-create-change-dialog tests', () => {
   let element: GrCreateChangeDialog;
diff --git a/polygerrit-ui/app/elements/admin/gr-create-group-dialog/gr-create-group-dialog_test.ts b/polygerrit-ui/app/elements/admin/gr-create-group-dialog/gr-create-group-dialog_test.ts
index e413d46..cb1d100 100644
--- a/polygerrit-ui/app/elements/admin/gr-create-group-dialog/gr-create-group-dialog_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-create-group-dialog/gr-create-group-dialog_test.ts
@@ -14,7 +14,7 @@
 } from '../../../test/test-utils';
 import {IronInputElement} from '@polymer/iron-input';
 import {GroupId} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-create-group-dialog tests', () => {
   let element: GrCreateGroupDialog;
diff --git a/polygerrit-ui/app/elements/admin/gr-create-pointer-dialog/gr-create-pointer-dialog_test.ts b/polygerrit-ui/app/elements/admin/gr-create-pointer-dialog/gr-create-pointer-dialog_test.ts
index d1ddcaf..ef28485 100644
--- a/polygerrit-ui/app/elements/admin/gr-create-pointer-dialog/gr-create-pointer-dialog_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-create-pointer-dialog/gr-create-pointer-dialog_test.ts
@@ -14,7 +14,7 @@
 import {BranchName} from '../../../types/common';
 import {IronInputElement} from '@polymer/iron-input';
 import {RepoDetailView} from '../../../utils/router-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-create-pointer-dialog tests', () => {
   let element: GrCreatePointerDialog;
diff --git a/polygerrit-ui/app/elements/admin/gr-create-repo-dialog/gr-create-repo-dialog_test.ts b/polygerrit-ui/app/elements/admin/gr-create-repo-dialog/gr-create-repo-dialog_test.ts
index aba71e3..0caa3ac 100644
--- a/polygerrit-ui/app/elements/admin/gr-create-repo-dialog/gr-create-repo-dialog_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-create-repo-dialog/gr-create-repo-dialog_test.ts
@@ -14,7 +14,7 @@
 import {BranchName, GroupId, RepoName} from '../../../types/common';
 import {GrAutocomplete} from '../../shared/gr-autocomplete/gr-autocomplete';
 import {GrSelect} from '../../shared/gr-select/gr-select';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-create-repo-dialog tests', () => {
   let element: GrCreateRepoDialog;
diff --git a/polygerrit-ui/app/elements/admin/gr-group-audit-log/gr-group-audit-log_test.ts b/polygerrit-ui/app/elements/admin/gr-group-audit-log/gr-group-audit-log_test.ts
index 08b434b..d37e7d0 100644
--- a/polygerrit-ui/app/elements/admin/gr-group-audit-log/gr-group-audit-log_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-group-audit-log/gr-group-audit-log_test.ts
@@ -23,7 +23,7 @@
   createGroupInfo,
 } from '../../../test/test-data-generators';
 import {PageErrorEvent} from '../../../types/events';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-group-audit-log tests', () => {
   let element: GrGroupAuditLog;
diff --git a/polygerrit-ui/app/elements/admin/gr-group-members/gr-group-members_test.ts b/polygerrit-ui/app/elements/admin/gr-group-members/gr-group-members_test.ts
index 8030ba9..e52d8b3 100644
--- a/polygerrit-ui/app/elements/admin/gr-group-members/gr-group-members_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-group-members/gr-group-members_test.ts
@@ -29,7 +29,7 @@
 import {EventType, PageErrorEvent} from '../../../types/events.js';
 import {getAccountSuggestions} from '../../../utils/account-util';
 import {getAppContext} from '../../../services/app-context';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-group-members tests', () => {
   let element: GrGroupMembers;
diff --git a/polygerrit-ui/app/elements/admin/gr-group/gr-group_test.ts b/polygerrit-ui/app/elements/admin/gr-group/gr-group_test.ts
index a7bbaff..e0b4d1d 100644
--- a/polygerrit-ui/app/elements/admin/gr-group/gr-group_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-group/gr-group_test.ts
@@ -19,7 +19,7 @@
 import {GrButton} from '../../shared/gr-button/gr-button';
 import {GrCopyClipboard} from '../../shared/gr-copy-clipboard/gr-copy-clipboard';
 import {GrSelect} from '../../shared/gr-select/gr-select';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-group tests', () => {
   let element: GrGroup;
diff --git a/polygerrit-ui/app/elements/admin/gr-permission/gr-permission_test.ts b/polygerrit-ui/app/elements/admin/gr-permission/gr-permission_test.ts
index b60cb1b..d50c3c1 100644
--- a/polygerrit-ui/app/elements/admin/gr-permission/gr-permission_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-permission/gr-permission_test.ts
@@ -17,7 +17,7 @@
 import {queryAndAssert} from '../../../test/test-utils';
 import {GrRuleEditor} from '../gr-rule-editor/gr-rule-editor';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-permission tests', () => {
   let element: GrPermission;
diff --git a/polygerrit-ui/app/elements/admin/gr-plugin-config-array-editor/gr-plugin-config-array-editor_test.ts b/polygerrit-ui/app/elements/admin/gr-plugin-config-array-editor/gr-plugin-config-array-editor_test.ts
index 4db4774..880837f 100644
--- a/polygerrit-ui/app/elements/admin/gr-plugin-config-array-editor/gr-plugin-config-array-editor_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-plugin-config-array-editor/gr-plugin-config-array-editor_test.ts
@@ -10,7 +10,7 @@
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {queryAll, queryAndAssert} from '../../../test/test-utils.js';
 import {GrButton} from '../../shared/gr-button/gr-button.js';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-plugin-config-array-editor tests', () => {
   let element: GrPluginConfigArrayEditor;
diff --git a/polygerrit-ui/app/elements/admin/gr-plugin-list/gr-plugin-list_test.ts b/polygerrit-ui/app/elements/admin/gr-plugin-list/gr-plugin-list_test.ts
index 7ac65f8..b6b6e9f 100644
--- a/polygerrit-ui/app/elements/admin/gr-plugin-list/gr-plugin-list_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-plugin-list/gr-plugin-list_test.ts
@@ -19,7 +19,7 @@
 import {GerritView} from '../../../services/router/router-model';
 import {PageErrorEvent} from '../../../types/events';
 import {SHOWN_ITEMS_COUNT} from '../../../constants/constants';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 function pluginGenerator(counter: number) {
   const plugin: PluginInfo = {
diff --git a/polygerrit-ui/app/elements/admin/gr-repo-access/gr-repo-access_test.ts b/polygerrit-ui/app/elements/admin/gr-repo-access/gr-repo-access_test.ts
index 4c1ba23..ac8280e 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo-access/gr-repo-access_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-repo-access/gr-repo-access_test.ts
@@ -31,7 +31,7 @@
 import {GrAccessSection} from '../gr-access-section/gr-access-section';
 import {GrPermission} from '../gr-permission/gr-permission';
 import {createChange} from '../../../test/test-data-generators';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-repo-access tests', () => {
   let element: GrRepoAccess;
diff --git a/polygerrit-ui/app/elements/admin/gr-repo-commands/gr-repo-commands_test.ts b/polygerrit-ui/app/elements/admin/gr-repo-commands/gr-repo-commands_test.ts
index 85aaa39..d498a17 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo-commands/gr-repo-commands_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-repo-commands/gr-repo-commands_test.ts
@@ -19,7 +19,7 @@
 import {EventType, PageErrorEvent} from '../../../types/events';
 import {RepoName} from '../../../types/common';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-repo-commands tests', () => {
   let element: GrRepoCommands;
diff --git a/polygerrit-ui/app/elements/admin/gr-repo-dashboards/gr-repo-dashboards_test.ts b/polygerrit-ui/app/elements/admin/gr-repo-dashboards/gr-repo-dashboards_test.ts
index 4cd6ba5..75f2c4d 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo-dashboards/gr-repo-dashboards_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-repo-dashboards/gr-repo-dashboards_test.ts
@@ -15,7 +15,7 @@
 } from '../../../test/test-utils';
 import {DashboardId, DashboardInfo, RepoName} from '../../../types/common';
 import {PageErrorEvent} from '../../../types/events.js';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-repo-dashboards tests', () => {
   let element: GrRepoDashboards;
diff --git a/polygerrit-ui/app/elements/admin/gr-repo-detail-list/gr-repo-detail-list_test.ts b/polygerrit-ui/app/elements/admin/gr-repo-detail-list/gr-repo-detail-list_test.ts
index 8cc4517..823ad8f 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo-detail-list/gr-repo-detail-list_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-repo-detail-list/gr-repo-detail-list_test.ts
@@ -36,7 +36,7 @@
 import {GrListView} from '../../shared/gr-list-view/gr-list-view';
 import {SHOWN_ITEMS_COUNT} from '../../../constants/constants';
 import {RepoDetailView} from '../../../utils/router-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 function branchGenerator(counter: number) {
   return {
diff --git a/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list_test.ts b/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list_test.ts
index 0a8f251..292c0ad 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list_test.ts
@@ -23,7 +23,7 @@
 import {GrOverlay} from '../../shared/gr-overlay/gr-overlay';
 import {GrDialog} from '../../shared/gr-dialog/gr-dialog';
 import {GrListView} from '../../shared/gr-list-view/gr-list-view';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 function createRepo(name: string, counter: number) {
   return {
diff --git a/polygerrit-ui/app/elements/admin/gr-repo-plugin-config/gr-repo-plugin-config_test.ts b/polygerrit-ui/app/elements/admin/gr-repo-plugin-config/gr-repo-plugin-config_test.ts
index 38d1c4f..c5a7fa1 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo-plugin-config/gr-repo-plugin-config_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-repo-plugin-config/gr-repo-plugin-config_test.ts
@@ -11,7 +11,7 @@
 import {queryAndAssert} from '../../../test/test-utils';
 import {GrPluginConfigArrayEditor} from '../gr-plugin-config-array-editor/gr-plugin-config-array-editor';
 import {PaperToggleButtonElement} from '@polymer/paper-toggle-button/paper-toggle-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-repo-plugin-config tests', () => {
   let element: GrRepoPluginConfig;
diff --git a/polygerrit-ui/app/elements/admin/gr-repo/gr-repo_test.ts b/polygerrit-ui/app/elements/admin/gr-repo/gr-repo_test.ts
index 6a10f78..4753e80 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo/gr-repo_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-repo/gr-repo_test.ts
@@ -44,7 +44,7 @@
 import {GrSelect} from '../../shared/gr-select/gr-select';
 import {GrTextarea} from '../../shared/gr-textarea/gr-textarea';
 import {IronInputElement} from '@polymer/iron-input/iron-input';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-repo tests', () => {
   let element: GrRepo;
diff --git a/polygerrit-ui/app/elements/admin/gr-rule-editor/gr-rule-editor_test.ts b/polygerrit-ui/app/elements/admin/gr-rule-editor/gr-rule-editor_test.ts
index a459df8..745aa6e 100644
--- a/polygerrit-ui/app/elements/admin/gr-rule-editor/gr-rule-editor_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-rule-editor/gr-rule-editor_test.ts
@@ -11,7 +11,7 @@
 import {GrButton} from '../../shared/gr-button/gr-button';
 import {GrSelect} from '../../shared/gr-select/gr-select';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EditablePermissionRuleInfo} from '../gr-repo-access/gr-repo-access-interfaces';
 import {PermissionAction} from '../../../constants/constants';
 
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-action-bar/gr-change-list-action-bar_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-action-bar/gr-change-list-action-bar_test.ts
index bfb30c6..4d6d6e9 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-action-bar/gr-change-list-action-bar_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-action-bar/gr-change-list-action-bar_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {
   BulkActionsModel,
   bulkActionsModelToken,
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-bulk-abandon-flow/gr-change-list-bulk-abandon-flow_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-bulk-abandon-flow/gr-change-list-bulk-abandon-flow_test.ts
index ded006e..25f9f63 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-bulk-abandon-flow/gr-change-list-bulk-abandon-flow_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-bulk-abandon-flow/gr-change-list-bulk-abandon-flow_test.ts
@@ -19,7 +19,7 @@
   LoadingState,
 } from '../../../models/bulk-actions/bulk-actions-model';
 import './gr-change-list-bulk-abandon-flow';
-import {fixture, waitUntil} from '@open-wc/testing';
+import {fixture, waitUntil, assert} from '@open-wc/testing';
 import {wrapInProvider} from '../../../models/di-provider-element';
 import {html} from 'lit';
 import {getAppContext} from '../../../services/app-context';
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-bulk-vote-flow/gr-change-list-bulk-vote-flow_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-bulk-vote-flow/gr-change-list-bulk-vote-flow_test.ts
index 048751b..afbdcc3 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-bulk-vote-flow/gr-change-list-bulk-vote-flow_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-bulk-vote-flow/gr-change-list-bulk-vote-flow_test.ts
@@ -21,7 +21,7 @@
 } from '../../../test/test-utils';
 import {ChangeInfo, NumericChangeId, LabelInfo} from '../../../api/rest-api';
 import {getAppContext} from '../../../services/app-context';
-import {fixture, waitUntil} from '@open-wc/testing';
+import {fixture, waitUntil, assert} from '@open-wc/testing';
 import {wrapInProvider} from '../../../models/di-provider-element';
 import {html} from 'lit';
 import {SinonStubbedMember} from 'sinon';
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-column-requirement/gr-change-list-column-requirement_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-column-requirement/gr-change-list-column-requirement_test.ts
index 92d2de0..10e75ab 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-column-requirement/gr-change-list-column-requirement_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-column-requirement/gr-change-list-column-requirement_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-change-list-column-requirement';
 import {GrChangeListColumnRequirement} from './gr-change-list-column-requirement';
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-column-requirements-summary/gr-change-list-column-requirements-summary_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-column-requirements-summary/gr-change-list-column-requirements-summary_test.ts
index e235fec..7b87cf8 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-column-requirements-summary/gr-change-list-column-requirements-summary_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-column-requirements-summary/gr-change-list-column-requirements-summary_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-change-list-column-requirements-summary';
 import {GrChangeListColumnRequirementsSummary} from './gr-change-list-column-requirements-summary';
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-hashtag-flow/gr-change-list-hashtag-flow_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-hashtag-flow/gr-change-list-hashtag-flow_test.ts
index 8ab07a6..a1d0732 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-hashtag-flow/gr-change-list-hashtag-flow_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-hashtag-flow/gr-change-list-hashtag-flow_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {IronDropdownElement} from '@polymer/iron-dropdown';
 import {SinonStubbedMember} from 'sinon';
 import {
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_test.ts
index 0f7e8c3..4da89d7 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import {
   SubmitRequirementResultInfo,
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-reviewer-flow/gr-change-list-reviewer-flow_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-reviewer-flow/gr-change-list-reviewer-flow_test.ts
index be0ea6e..7db8818 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-reviewer-flow/gr-change-list-reviewer-flow_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-reviewer-flow/gr-change-list-reviewer-flow_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {SinonStubbedMember} from 'sinon';
 import {
   AccountInfo,
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-section/gr-change-list-section_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-section/gr-change-list-section_test.ts
index 684f37f..d1122c7 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-section/gr-change-list-section_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-section/gr-change-list-section_test.ts
@@ -25,7 +25,7 @@
 } from '../../../test/test-utils';
 import {GrChangeListItem} from '../gr-change-list-item/gr-change-list-item';
 import {ChangeListSection} from '../gr-change-list/gr-change-list';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {ColumnNames} from '../../../constants/constants';
 
 suite('gr-change-list section', () => {
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-topic-flow/gr-change-list-topic-flow_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-topic-flow/gr-change-list-topic-flow_test.ts
index f49787d..d7a4a2b 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-topic-flow/gr-change-list-topic-flow_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-topic-flow/gr-change-list-topic-flow_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {IronDropdownElement} from '@polymer/iron-dropdown';
 import {SinonStubbedMember} from 'sinon';
 import {
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view_test.ts
index 3cc7f40..4c21dfd 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view_test.ts
@@ -23,7 +23,7 @@
   RepoName,
 } from '../../../api/rest-api.js';
 import {tap} from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html, waitUntil} from '@open-wc/testing';
+import {fixture, html, waitUntil, assert} from '@open-wc/testing';
 import {GerritView} from '../../../services/router/router-model.js';
 
 const CHANGE_ID = 'IcA3dAB3edAB9f60B8dcdA6ef71A75980e4B7127';
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.ts b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.ts
index 4f6e6d5..8c52263 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.ts
@@ -30,7 +30,7 @@
 import {GrChangeListItem} from '../gr-change-list-item/gr-change-list-item';
 import {GrChangeListSection} from '../gr-change-list-section/gr-change-list-section';
 import {getAppContext} from '../../../services/app-context';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {wrapInProvider} from '../../../models/di-provider-element';
 import {
   ShortcutsService,
diff --git a/polygerrit-ui/app/elements/change-list/gr-create-change-help/gr-create-change-help_test.ts b/polygerrit-ui/app/elements/change-list/gr-create-change-help/gr-create-change-help_test.ts
index b896a33..f4c2c0f 100644
--- a/polygerrit-ui/app/elements/change-list/gr-create-change-help/gr-create-change-help_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-create-change-help/gr-create-change-help_test.ts
@@ -9,7 +9,7 @@
 import {mockPromise, queryAndAssert} from '../../../test/test-utils';
 import {GrButton} from '../../shared/gr-button/gr-button';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-create-change-help tests', () => {
   let element: GrCreateChangeHelp;
diff --git a/polygerrit-ui/app/elements/change-list/gr-create-commands-dialog/gr-create-commands-dialog_test.ts b/polygerrit-ui/app/elements/change-list/gr-create-commands-dialog/gr-create-commands-dialog_test.ts
index 93c48b3..1bb6465 100644
--- a/polygerrit-ui/app/elements/change-list/gr-create-commands-dialog/gr-create-commands-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-create-commands-dialog/gr-create-commands-dialog_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import './gr-create-commands-dialog';
 import {GrCreateCommandsDialog} from './gr-create-commands-dialog';
diff --git a/polygerrit-ui/app/elements/change-list/gr-create-destination-dialog/gr-create-destination-dialog_test.ts b/polygerrit-ui/app/elements/change-list/gr-create-destination-dialog/gr-create-destination-dialog_test.ts
index ed876db..9c4e23fc 100644
--- a/polygerrit-ui/app/elements/change-list/gr-create-destination-dialog/gr-create-destination-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-create-destination-dialog/gr-create-destination-dialog_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import './gr-create-destination-dialog';
 import {GrCreateDestinationDialog} from './gr-create-destination-dialog';
 
diff --git a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view_test.ts b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view_test.ts
index bcc5367..6c9070e 100644
--- a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view_test.ts
@@ -34,7 +34,7 @@
 import {GrDialog} from '../../shared/gr-dialog/gr-dialog';
 import {GrCreateChangeHelp} from '../gr-create-change-help/gr-create-change-help';
 import {PageErrorEvent} from '../../../types/events';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {SinonStubbedMember} from 'sinon';
 import {RestApiService} from '../../../services/gr-rest-api/gr-rest-api';
 
diff --git a/polygerrit-ui/app/elements/change-list/gr-repo-header/gr-repo-header_test.ts b/polygerrit-ui/app/elements/change-list/gr-repo-header/gr-repo-header_test.ts
index d5f9877..6fa0a9f 100644
--- a/polygerrit-ui/app/elements/change-list/gr-repo-header/gr-repo-header_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-repo-header/gr-repo-header_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import './gr-repo-header';
 import {GrRepoHeader} from './gr-repo-header';
 import {GerritNav} from '../../core/gr-navigation/gr-navigation';
diff --git a/polygerrit-ui/app/elements/change-list/gr-user-header/gr-user-header_test.ts b/polygerrit-ui/app/elements/change-list/gr-user-header/gr-user-header_test.ts
index 3528d11..1fe4848 100644
--- a/polygerrit-ui/app/elements/change-list/gr-user-header/gr-user-header_test.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-user-header/gr-user-header_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import './gr-user-header';
 import {GrUserHeader} from './gr-user-header';
 import {stubRestApi} from '../../../test/test-utils';
diff --git a/polygerrit-ui/app/elements/change/gr-change-actions/gr-change-actions_test.ts b/polygerrit-ui/app/elements/change/gr-change-actions/gr-change-actions_test.ts
index 4d43504..3f0fda3 100644
--- a/polygerrit-ui/app/elements/change/gr-change-actions/gr-change-actions_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-actions/gr-change-actions_test.ts
@@ -49,7 +49,7 @@
 import {GrDialog} from '../../shared/gr-dialog/gr-dialog';
 import {UIActionInfo} from '../../shared/gr-js-api-interface/gr-change-actions-js-api';
 import {getAppContext} from '../../../services/app-context';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrConfirmCherrypickDialog} from '../gr-confirm-cherrypick-dialog/gr-confirm-cherrypick-dialog';
 import {GrDropdown} from '../../shared/gr-dropdown/gr-dropdown';
 import {GrOverlay} from '../../shared/gr-overlay/gr-overlay';
diff --git a/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_test.ts b/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_test.ts
index 8c89aab..bf8d0b0 100644
--- a/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_test.ts
@@ -57,7 +57,7 @@
 import {GrButton} from '../../shared/gr-button/gr-button';
 import {GrRouter} from '../../core/gr-router/gr-router';
 import {nothing} from 'lit';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EventType} from '../../../types/events';
 
 suite('gr-change-metadata tests', () => {
diff --git a/polygerrit-ui/app/elements/change/gr-change-summary/gr-change-summary_test.ts b/polygerrit-ui/app/elements/change/gr-change-summary/gr-change-summary_test.ts
index ed1f206..d476607 100644
--- a/polygerrit-ui/app/elements/change/gr-change-summary/gr-change-summary_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-summary/gr-change-summary_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrChangeSummary} from './gr-change-summary';
 import {queryAndAssert} from '../../../utils/common-util';
 import {fakeRun0} from '../../../models/checks/checks-fakes';
diff --git a/polygerrit-ui/app/elements/change/gr-change-summary/gr-checks-chip_test.ts b/polygerrit-ui/app/elements/change/gr-change-summary/gr-checks-chip_test.ts
index 60526da..37c57cd 100644
--- a/polygerrit-ui/app/elements/change/gr-change-summary/gr-checks-chip_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-summary/gr-checks-chip_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrChecksChip} from './gr-checks-chip';
 import {Category} from '../../../api/checks';
 
diff --git a/polygerrit-ui/app/elements/change/gr-change-summary/gr-summary-chip_test.ts b/polygerrit-ui/app/elements/change/gr-change-summary/gr-summary-chip_test.ts
index b12bafc..562b4ea 100644
--- a/polygerrit-ui/app/elements/change/gr-change-summary/gr-summary-chip_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-summary/gr-summary-chip_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrSummaryChip, SummaryChipStyles} from './gr-summary-chip';
 import {CommentTabState} from '../../../types/events';
 
diff --git a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view_test.ts b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view_test.ts
index 5135262..cb3fefc 100644
--- a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view_test.ts
@@ -95,7 +95,7 @@
 import {GrThreadList} from '../gr-thread-list/gr-thread-list';
 import {assertIsDefined} from '../../../utils/common-util';
 import {DEFAULT_NUM_FILES_SHOWN} from '../gr-file-list/gr-file-list';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {deepClone} from '../../../utils/deep-util';
 
 suite('gr-change-view tests', () => {
diff --git a/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info_test.ts b/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info_test.ts
index f15094e..79baabf 100644
--- a/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info_test.ts
@@ -14,7 +14,7 @@
 } from '../../../test/test-data-generators';
 import {CommitId, RepoName} from '../../../types/common';
 import {GrRouter} from '../../core/gr-router/gr-router';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-commit-info tests', () => {
   let element: GrCommitInfo;
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-abandon-dialog/gr-confirm-abandon-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-confirm-abandon-dialog/gr-confirm-abandon-dialog_test.ts
index 9df4c73..06d8c3c 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-abandon-dialog/gr-confirm-abandon-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-abandon-dialog/gr-confirm-abandon-dialog_test.ts
@@ -8,7 +8,7 @@
 import {GrConfirmAbandonDialog} from './gr-confirm-abandon-dialog';
 import {queryAndAssert} from '../../../test/test-utils';
 import {GrDialog} from '../../shared/gr-dialog/gr-dialog';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-confirm-abandon-dialog tests', () => {
   let element: GrConfirmAbandonDialog;
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-cherrypick-conflict-dialog/gr-confirm-cherrypick-conflict-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-confirm-cherrypick-conflict-dialog/gr-confirm-cherrypick-conflict-dialog_test.ts
index b1623db..7e8fa66 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-cherrypick-conflict-dialog/gr-confirm-cherrypick-conflict-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-cherrypick-conflict-dialog/gr-confirm-cherrypick-conflict-dialog_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import {queryAndAssert} from '../../../utils/common-util';
 import './gr-confirm-cherrypick-conflict-dialog';
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-cherrypick-dialog/gr-confirm-cherrypick-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-confirm-cherrypick-dialog/gr-confirm-cherrypick-dialog_test.ts
index 1d23cff..e2047a6 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-cherrypick-dialog/gr-confirm-cherrypick-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-cherrypick-dialog/gr-confirm-cherrypick-dialog_test.ts
@@ -24,7 +24,7 @@
 import {GrDialog} from '../../shared/gr-dialog/gr-dialog.js';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {ProgressStatus} from '../../../constants/constants';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 const CHERRY_PICK_TYPES = {
   SINGLE_CHANGE: 1,
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-move-dialog/gr-confirm-move-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-confirm-move-dialog/gr-confirm-move-dialog_test.ts
index d627e19..74389d6 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-move-dialog/gr-confirm-move-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-move-dialog/gr-confirm-move-dialog_test.ts
@@ -8,7 +8,7 @@
 import {GrConfirmMoveDialog} from './gr-confirm-move-dialog';
 import {queryAndAssert, stubRestApi} from '../../../test/test-utils';
 import {BranchName, GitRef, RepoName} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrAutocomplete} from '../../shared/gr-autocomplete/gr-autocomplete';
 
 suite('gr-confirm-move-dialog tests', () => {
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-rebase-dialog/gr-confirm-rebase-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-confirm-rebase-dialog/gr-confirm-rebase-dialog_test.ts
index 0a89118..78ec2eb 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-rebase-dialog/gr-confirm-rebase-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-rebase-dialog/gr-confirm-rebase-dialog_test.ts
@@ -10,7 +10,7 @@
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {NumericChangeId, BranchName} from '../../../types/common';
 import {createChangeViewChange} from '../../../test/test-data-generators';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-confirm-rebase-dialog tests', () => {
   let element: GrConfirmRebaseDialog;
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-revert-dialog/gr-confirm-revert-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-confirm-revert-dialog/gr-confirm-revert-dialog_test.ts
index c5ba496..0b06ebf 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-revert-dialog/gr-confirm-revert-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-revert-dialog/gr-confirm-revert-dialog_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import {createChange} from '../../../test/test-data-generators';
 import {CommitId} from '../../../types/common';
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-submit-dialog/gr-confirm-submit-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-confirm-submit-dialog/gr-confirm-submit-dialog_test.ts
index e9924b5..3e72714 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-submit-dialog/gr-confirm-submit-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-submit-dialog/gr-confirm-submit-dialog_test.ts
@@ -12,7 +12,7 @@
 import {EDIT} from '../../../types/common';
 import {GrConfirmSubmitDialog} from './gr-confirm-submit-dialog';
 import './gr-confirm-submit-dialog';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-confirm-submit-dialog tests', () => {
   let element: GrConfirmSubmitDialog;
diff --git a/polygerrit-ui/app/elements/change/gr-download-dialog/gr-download-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-download-dialog/gr-download-dialog_test.ts
index 4343874..1759342 100644
--- a/polygerrit-ui/app/elements/change/gr-download-dialog/gr-download-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-download-dialog/gr-download-dialog_test.ts
@@ -21,7 +21,7 @@
 import {GrDownloadDialog} from './gr-download-dialog';
 import {mockPromise, queryAll, queryAndAssert} from '../../../test/test-utils';
 import {GrDownloadCommands} from '../../shared/gr-download-commands/gr-download-commands';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 function getChangeObject() {
   return {
diff --git a/polygerrit-ui/app/elements/change/gr-file-list-header/gr-file-list-header_test.ts b/polygerrit-ui/app/elements/change/gr-file-list-header/gr-file-list-header_test.ts
index e51df4b..2005682 100644
--- a/polygerrit-ui/app/elements/change/gr-file-list-header/gr-file-list-header_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-file-list-header/gr-file-list-header_test.ts
@@ -27,7 +27,7 @@
 import {ChangeInfo, ChangeStatus} from '../../../api/rest-api';
 import {PatchSet} from '../../../utils/patch-set-util';
 import {createDefaultDiffPrefs} from '../../../constants/constants';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrButton} from '../../shared/gr-button/gr-button';
 
 suite('gr-file-list-header tests', () => {
diff --git a/polygerrit-ui/app/elements/change/gr-included-in-dialog/gr-included-in-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-included-in-dialog/gr-included-in-dialog_test.ts
index 23bb9ea..faed2bd 100644
--- a/polygerrit-ui/app/elements/change/gr-included-in-dialog/gr-included-in-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-included-in-dialog/gr-included-in-dialog_test.ts
@@ -9,7 +9,7 @@
 import {BranchName, IncludedInInfo, TagName} from '../../../types/common';
 import {IronInputElement} from '@polymer/iron-input';
 import {queryAndAssert} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-included-in-dialog', () => {
   let element: GrIncludedInDialog;
diff --git a/polygerrit-ui/app/elements/change/gr-label-score-row/gr-label-score-row_test.ts b/polygerrit-ui/app/elements/change/gr-label-score-row/gr-label-score-row_test.ts
index 8edcaf2..ef765b6 100644
--- a/polygerrit-ui/app/elements/change/gr-label-score-row/gr-label-score-row_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-label-score-row/gr-label-score-row_test.ts
@@ -8,7 +8,7 @@
 import {GrLabelScoreRow} from './gr-label-score-row';
 import {AccountId} from '../../../api/rest-api';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-label-row-score tests', () => {
   let element: GrLabelScoreRow;
diff --git a/polygerrit-ui/app/elements/change/gr-label-scores/gr-label-scores_test.ts b/polygerrit-ui/app/elements/change/gr-label-scores/gr-label-scores_test.ts
index 21caf8f..9865e41 100644
--- a/polygerrit-ui/app/elements/change/gr-label-scores/gr-label-scores_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-label-scores/gr-label-scores_test.ts
@@ -15,7 +15,7 @@
 } from '../../../test/test-data-generators';
 import {ChangeStatus} from '../../../constants/constants';
 import {getVoteForAccount} from '../../../utils/label-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-label-scores tests', () => {
   const accountId = 123 as AccountId;
diff --git a/polygerrit-ui/app/elements/change/gr-message-scores/gr-message-scores_test.ts b/polygerrit-ui/app/elements/change/gr-message-scores/gr-message-scores_test.ts
index 33c1719..f045a75 100644
--- a/polygerrit-ui/app/elements/change/gr-message-scores/gr-message-scores_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-message-scores/gr-message-scores_test.ts
@@ -12,7 +12,7 @@
 } from '../../../test/test-data-generators';
 import {queryAll, stubFlags} from '../../../test/test-utils';
 import {GrMessageScores} from './gr-message-scores';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-message-score tests', () => {
   let element: GrMessageScores;
diff --git a/polygerrit-ui/app/elements/change/gr-message/gr-message_test.ts b/polygerrit-ui/app/elements/change/gr-message/gr-message_test.ts
index 66fd332..13c657b 100644
--- a/polygerrit-ui/app/elements/change/gr-message/gr-message_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-message/gr-message_test.ts
@@ -43,7 +43,7 @@
 import {CommentSide} from '../../../constants/constants';
 import {SinonStubbedMember} from 'sinon';
 import {html} from 'lit';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 
 suite('gr-message tests', () => {
   let element: GrMessage;
diff --git a/polygerrit-ui/app/elements/change/gr-messages-list/gr-messages-list_test.ts b/polygerrit-ui/app/elements/change/gr-messages-list/gr-messages-list_test.ts
index 24a2e64..76ebaaf 100644
--- a/polygerrit-ui/app/elements/change/gr-messages-list/gr-messages-list_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-messages-list/gr-messages-list_test.ts
@@ -30,7 +30,7 @@
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {assertIsDefined} from '../../../utils/common-util';
 import {html} from 'lit';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 
 const author = {
   _account_id: 42 as AccountId,
diff --git a/polygerrit-ui/app/elements/change/gr-related-changes-list/gr-related-changes-list_test.ts b/polygerrit-ui/app/elements/change/gr-related-changes-list/gr-related-changes-list_test.ts
index 7d25d06..58893f5 100644
--- a/polygerrit-ui/app/elements/change/gr-related-changes-list/gr-related-changes-list_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-related-changes-list/gr-related-changes-list_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {SinonStubbedMember} from 'sinon';
 import {PluginApi} from '../../../api/plugin';
 import {ChangeStatus} from '../../../constants/constants';
diff --git a/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog-it_test.ts b/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog-it_test.ts
index b2cfdda..cdb65c2 100644
--- a/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog-it_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog-it_test.ts
@@ -12,7 +12,7 @@
 } from '../../../test/test-utils';
 import {getPluginLoader} from '../../shared/gr-js-api-interface/gr-plugin-loader';
 import {GrReplyDialog} from './gr-reply-dialog';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {
   AccountId,
   NumericChangeId,
diff --git a/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog_test.ts b/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog_test.ts
index fd4375d..d968106 100644
--- a/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog_test.ts
@@ -61,7 +61,7 @@
 import {GrLabelScores} from '../gr-label-scores/gr-label-scores';
 import {GrThreadList} from '../gr-thread-list/gr-thread-list';
 import {GrAutocomplete} from '../../shared/gr-autocomplete/gr-autocomplete';
-import {fixture, html, waitUntil} from '@open-wc/testing';
+import {fixture, html, waitUntil, assert} from '@open-wc/testing';
 import {accountKey} from '../../../utils/account-util';
 import {GrButton} from '../../shared/gr-button/gr-button';
 import {GrAccountLabel} from '../../shared/gr-account-label/gr-account-label';
diff --git a/polygerrit-ui/app/elements/change/gr-reviewer-list/gr-reviewer-list_test.ts b/polygerrit-ui/app/elements/change/gr-reviewer-list/gr-reviewer-list_test.ts
index 4eea066..cb2b8e3 100644
--- a/polygerrit-ui/app/elements/change/gr-reviewer-list/gr-reviewer-list_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-reviewer-list/gr-reviewer-list_test.ts
@@ -14,7 +14,7 @@
 import {GrButton} from '../../shared/gr-button/gr-button';
 import {AccountId, EmailAddress} from '../../../types/common';
 import './gr-reviewer-list';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-reviewer-list tests', () => {
   let element: GrReviewerList;
diff --git a/polygerrit-ui/app/elements/change/gr-submit-requirement-dashboard-hovercard/gr-submit-requirement-dashboard-hovercard_test.ts b/polygerrit-ui/app/elements/change/gr-submit-requirement-dashboard-hovercard/gr-submit-requirement-dashboard-hovercard_test.ts
index f301059..15c3efd 100644
--- a/polygerrit-ui/app/elements/change/gr-submit-requirement-dashboard-hovercard/gr-submit-requirement-dashboard-hovercard_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-submit-requirement-dashboard-hovercard/gr-submit-requirement-dashboard-hovercard_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-submit-requirement-dashboard-hovercard';
 import {GrSubmitRequirementDashboardHovercard} from './gr-submit-requirement-dashboard-hovercard';
diff --git a/polygerrit-ui/app/elements/change/gr-submit-requirement-hovercard/gr-submit-requirement-hovercard_test.ts b/polygerrit-ui/app/elements/change/gr-submit-requirement-hovercard/gr-submit-requirement-hovercard_test.ts
index 9e028e5..8783dcb 100644
--- a/polygerrit-ui/app/elements/change/gr-submit-requirement-hovercard/gr-submit-requirement-hovercard_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-submit-requirement-hovercard/gr-submit-requirement-hovercard_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-submit-requirement-hovercard';
 import {GrSubmitRequirementHovercard} from './gr-submit-requirement-hovercard';
diff --git a/polygerrit-ui/app/elements/change/gr-submit-requirements/gr-submit-requirements_test.ts b/polygerrit-ui/app/elements/change/gr-submit-requirements/gr-submit-requirements_test.ts
index 9b4062a..48d7d7d 100644
--- a/polygerrit-ui/app/elements/change/gr-submit-requirements/gr-submit-requirements_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-submit-requirements/gr-submit-requirements_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-submit-requirements';
 import {GrSubmitRequirements} from './gr-submit-requirements';
diff --git a/polygerrit-ui/app/elements/change/gr-thread-list/gr-thread-list_test.ts b/polygerrit-ui/app/elements/change/gr-thread-list/gr-thread-list_test.ts
index e6d7455..ebc8bf3 100644
--- a/polygerrit-ui/app/elements/change/gr-thread-list/gr-thread-list_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-thread-list/gr-thread-list_test.ts
@@ -38,7 +38,7 @@
 import {query, queryAndAssert} from '../../../utils/common-util';
 import {GrAccountLabel} from '../../shared/gr-account-label/gr-account-label';
 import {GrDropdownList} from '../../shared/gr-dropdown-list/gr-dropdown-list';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-thread-list tests', () => {
   let element: GrThreadList;
diff --git a/polygerrit-ui/app/elements/change/gr-trigger-vote-hovercard/gr-trigger-vote-hovercard_test.ts b/polygerrit-ui/app/elements/change/gr-trigger-vote-hovercard/gr-trigger-vote-hovercard_test.ts
index 89a93b3..a97834c 100644
--- a/polygerrit-ui/app/elements/change/gr-trigger-vote-hovercard/gr-trigger-vote-hovercard_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-trigger-vote-hovercard/gr-trigger-vote-hovercard_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-trigger-vote-hovercard';
 import {GrTriggerVoteHovercard} from './gr-trigger-vote-hovercard';
diff --git a/polygerrit-ui/app/elements/change/gr-trigger-vote/gr-trigger-vote_test.ts b/polygerrit-ui/app/elements/change/gr-trigger-vote/gr-trigger-vote_test.ts
index 277d16b..520d793 100644
--- a/polygerrit-ui/app/elements/change/gr-trigger-vote/gr-trigger-vote_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-trigger-vote/gr-trigger-vote_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-trigger-vote';
 import {GrTriggerVote} from './gr-trigger-vote';
diff --git a/polygerrit-ui/app/elements/checks/gr-checks-results_test.ts b/polygerrit-ui/app/elements/checks/gr-checks-results_test.ts
index c4ccb0d..5fcab03 100644
--- a/polygerrit-ui/app/elements/checks/gr-checks-results_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-checks-results_test.ts
@@ -7,7 +7,7 @@
 import './gr-checks-results';
 import {GrChecksResults, GrResultRow} from './gr-checks-results';
 import {html} from 'lit';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {checksModelToken} from '../../models/checks/checks-model';
 import {fakeRun0, setAllFakeRuns} from '../../models/checks/checks-fakes';
 import {resolve} from '../../models/dependency';
diff --git a/polygerrit-ui/app/elements/checks/gr-checks-runs_test.ts b/polygerrit-ui/app/elements/checks/gr-checks-runs_test.ts
index 578b952..1244a2f 100644
--- a/polygerrit-ui/app/elements/checks/gr-checks-runs_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-checks-runs_test.ts
@@ -7,7 +7,7 @@
 import './gr-checks-runs';
 import {GrChecksRuns} from './gr-checks-runs';
 import {html} from 'lit';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {checksModelToken} from '../../models/checks/checks-model';
 import {setAllFakeRuns} from '../../models/checks/checks-fakes';
 import {resolve} from '../../models/dependency';
diff --git a/polygerrit-ui/app/elements/checks/gr-checks-tab_test.ts b/polygerrit-ui/app/elements/checks/gr-checks-tab_test.ts
index 2a77468..e797265 100644
--- a/polygerrit-ui/app/elements/checks/gr-checks-tab_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-checks-tab_test.ts
@@ -7,7 +7,7 @@
 import {html} from 'lit';
 import './gr-checks-tab';
 import {GrChecksTab} from './gr-checks-tab';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {checksModelToken} from '../../models/checks/checks-model';
 import {fakeRun4_3, setAllFakeRuns} from '../../models/checks/checks-fakes';
 import {resolve} from '../../models/dependency';
diff --git a/polygerrit-ui/app/elements/checks/gr-checks-util_test.ts b/polygerrit-ui/app/elements/checks/gr-checks-util_test.ts
index 44f4f79..1aed1fc 100644
--- a/polygerrit-ui/app/elements/checks/gr-checks-util_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-checks-util_test.ts
@@ -7,6 +7,7 @@
 import {createRunResult} from '../../test/test-data-generators';
 import {matches} from './gr-checks-util';
 import {RunResult} from '../../models/checks/checks-model';
+import {assert} from '@open-wc/testing';
 
 suite('gr-checks-util test', () => {
   test('regexp filter matching results', () => {
diff --git a/polygerrit-ui/app/elements/checks/gr-diff-check-result_test.ts b/polygerrit-ui/app/elements/checks/gr-diff-check-result_test.ts
index 994f42e..076f07b 100644
--- a/polygerrit-ui/app/elements/checks/gr-diff-check-result_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-diff-check-result_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {fakeRun1} from '../../models/checks/checks-fakes';
 import {RunResult} from '../../models/checks/checks-model';
 import '../../test/common-test-setup-karma';
diff --git a/polygerrit-ui/app/elements/checks/gr-hovercard-run_test.ts b/polygerrit-ui/app/elements/checks/gr-hovercard-run_test.ts
index 2b8bd63..da57d5a 100644
--- a/polygerrit-ui/app/elements/checks/gr-hovercard-run_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-hovercard-run_test.ts
@@ -5,7 +5,7 @@
  */
 import '../../test/common-test-setup-karma';
 import './gr-hovercard-run';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrHovercardRun} from './gr-hovercard-run';
 import {fakeRun0} from '../../models/checks/checks-fakes';
 
diff --git a/polygerrit-ui/app/elements/core/gr-account-dropdown/gr-account-dropdown_test.ts b/polygerrit-ui/app/elements/core/gr-account-dropdown/gr-account-dropdown_test.ts
index 041441b..03cefd2 100644
--- a/polygerrit-ui/app/elements/core/gr-account-dropdown/gr-account-dropdown_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-account-dropdown/gr-account-dropdown_test.ts
@@ -5,7 +5,7 @@
  */
 import '../../../test/common-test-setup-karma';
 import './gr-account-dropdown';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrAccountDropdown} from './gr-account-dropdown';
 import {AccountInfo} from '../../../types/common';
 import {createServerInfo} from '../../../test/test-data-generators';
diff --git a/polygerrit-ui/app/elements/core/gr-error-dialog/gr-error-dialog_test.ts b/polygerrit-ui/app/elements/core/gr-error-dialog/gr-error-dialog_test.ts
index 900746f..e69113e 100644
--- a/polygerrit-ui/app/elements/core/gr-error-dialog/gr-error-dialog_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-error-dialog/gr-error-dialog_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import '../../../test/common-test-setup-karma';
 import {mockPromise, queryAndAssert} from '../../../test/test-utils';
diff --git a/polygerrit-ui/app/elements/core/gr-error-manager/gr-error-manager_test.ts b/polygerrit-ui/app/elements/core/gr-error-manager/gr-error-manager_test.ts
index fb147d8..f392f97 100644
--- a/polygerrit-ui/app/elements/core/gr-error-manager/gr-error-manager_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-error-manager/gr-error-manager_test.ts
@@ -19,7 +19,7 @@
 import {tap} from '@polymer/iron-test-helpers/mock-interactions';
 import {AccountId} from '../../../types/common';
 import {waitUntil} from '../../../test/test-utils';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import {EventType} from '../../../types/events';
 
diff --git a/polygerrit-ui/app/elements/core/gr-key-binding-display/gr-key-binding-display_test.ts b/polygerrit-ui/app/elements/core/gr-key-binding-display/gr-key-binding-display_test.ts
index 77ee4bb..1f0d6b9 100644
--- a/polygerrit-ui/app/elements/core/gr-key-binding-display/gr-key-binding-display_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-key-binding-display/gr-key-binding-display_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import './gr-key-binding-display';
 import {GrKeyBindingDisplay} from './gr-key-binding-display';
diff --git a/polygerrit-ui/app/elements/core/gr-keyboard-shortcuts-dialog/gr-keyboard-shortcuts-dialog_test.ts b/polygerrit-ui/app/elements/core/gr-keyboard-shortcuts-dialog/gr-keyboard-shortcuts-dialog_test.ts
index d80e3d9..7c1e394 100644
--- a/polygerrit-ui/app/elements/core/gr-keyboard-shortcuts-dialog/gr-keyboard-shortcuts-dialog_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-keyboard-shortcuts-dialog/gr-keyboard-shortcuts-dialog_test.ts
@@ -10,7 +10,7 @@
   SectionView,
   ShortcutSection,
 } from '../../../services/shortcuts/shortcuts-service';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 const x = ['x'];
 const ctrlX = ['Ctrl', 'x'];
diff --git a/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.ts b/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.ts
index 4ea5e9c..638edab 100644
--- a/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.ts
@@ -20,7 +20,7 @@
 import {NavLink} from '../../../utils/admin-nav-util';
 import {ServerInfo, TopMenuItemInfo} from '../../../types/common';
 import {AuthType} from '../../../constants/constants';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-main-header tests', () => {
   let element: GrMainHeader;
diff --git a/polygerrit-ui/app/elements/core/gr-navigation/gr-navigation_test.ts b/polygerrit-ui/app/elements/core/gr-navigation/gr-navigation_test.ts
index 522ce0d..108710a 100644
--- a/polygerrit-ui/app/elements/core/gr-navigation/gr-navigation_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-navigation/gr-navigation_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import {createChange} from '../../../test/test-data-generators';
 import {BasePatchSetNum, NumericChangeId} from '../../../types/common';
diff --git a/polygerrit-ui/app/elements/core/gr-router/gr-router_test.ts b/polygerrit-ui/app/elements/core/gr-router/gr-router_test.ts
index 02d312f..c8581df 100644
--- a/polygerrit-ui/app/elements/core/gr-router/gr-router_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-router/gr-router_test.ts
@@ -42,6 +42,7 @@
   GenerateUrlChangeViewParameters,
   RepoDetailView,
 } from '../../../utils/router-util';
+import {assert} from '@open-wc/testing';
 
 suite('gr-router tests', () => {
   let router: GrRouter;
diff --git a/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts b/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
index 7802ef9..6f90740 100644
--- a/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
@@ -17,7 +17,7 @@
 import {queryAndAssert} from '../../../test/test-utils';
 import {GrAutocomplete} from '../../shared/gr-autocomplete/gr-autocomplete';
 import {PaperInputElement} from '@polymer/paper-input/paper-input';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-search-bar tests', () => {
   let element: GrSearchBar;
diff --git a/polygerrit-ui/app/elements/core/gr-smart-search/gr-smart-search_test.ts b/polygerrit-ui/app/elements/core/gr-smart-search/gr-smart-search_test.ts
index f468778..7b889a0 100644
--- a/polygerrit-ui/app/elements/core/gr-smart-search/gr-smart-search_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-smart-search/gr-smart-search_test.ts
@@ -8,7 +8,7 @@
 import {GrSmartSearch} from './gr-smart-search';
 import {stubRestApi} from '../../../test/test-utils';
 import {EmailAddress, GroupId, UrlEncodedRepoName} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-smart-search tests', () => {
   let element: GrSmartSearch;
diff --git a/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog_test.ts b/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog_test.ts
index 8338cff..7566f8e 100644
--- a/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog_test.ts
+++ b/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog_test.ts
@@ -23,7 +23,7 @@
   OpenFixPreviewEventDetail,
 } from '../../../types/events';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-apply-fix-dialog tests', () => {
   let element: GrApplyFixDialog;
diff --git a/polygerrit-ui/app/elements/diff/gr-comment-api/gr-comment-api_test.ts b/polygerrit-ui/app/elements/diff/gr-comment-api/gr-comment-api_test.ts
index b195762..2e54e5d 100644
--- a/polygerrit-ui/app/elements/diff/gr-comment-api/gr-comment-api_test.ts
+++ b/polygerrit-ui/app/elements/diff/gr-comment-api/gr-comment-api_test.ts
@@ -36,6 +36,7 @@
   UrlEncodedCommentId,
 } from '../../../types/common';
 import {stubRestApi} from '../../../test/test-utils';
+import {assert} from '@open-wc/testing';
 
 suite('ChangeComments tests', () => {
   let changeComments: ChangeComments;
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host_test.ts b/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host_test.ts
index acc0638..fe4c0cd 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host_test.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host_test.ts
@@ -54,7 +54,7 @@
 import {GrCommentThread} from '../../shared/gr-comment-thread/gr-comment-thread';
 import {assertIsDefined} from '../../../utils/common-util';
 import {GrAnnotationActionsInterface} from '../../shared/gr-js-api-interface/gr-annotation-actions-js-api';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EventType} from '../../../types/events';
 
 suite('gr-diff-host tests', () => {
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-preferences-dialog/gr-diff-preferences-dialog_test.ts b/polygerrit-ui/app/elements/diff/gr-diff-preferences-dialog/gr-diff-preferences-dialog_test.ts
index fe4517e..1458fc5 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-preferences-dialog/gr-diff-preferences-dialog_test.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-preferences-dialog/gr-diff-preferences-dialog_test.ts
@@ -11,7 +11,7 @@
 import {DiffPreferencesInfo} from '../../../api/diff';
 import {ParsedJSON} from '../../../types/common';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-diff-preferences-dialog', () => {
   let element: GrDiffPreferencesDialog;
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.ts b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.ts
index f10ec86..a426523 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.ts
@@ -65,7 +65,7 @@
 import {ParsedChangeInfo} from '../../../types/types';
 import {assertIsDefined} from '../../../utils/common-util';
 import {GrDiffModeSelector} from '../../../embed/diff/gr-diff-mode-selector/gr-diff-mode-selector';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EventType} from '../../../types/events';
 
 function createComment(
diff --git a/polygerrit-ui/app/elements/diff/gr-patch-range-select/gr-patch-range-select_test.ts b/polygerrit-ui/app/elements/diff/gr-patch-range-select/gr-patch-range-select_test.ts
index c4b2a60..6e7efba 100644
--- a/polygerrit-ui/app/elements/diff/gr-patch-range-select/gr-patch-range-select_test.ts
+++ b/polygerrit-ui/app/elements/diff/gr-patch-range-select/gr-patch-range-select_test.ts
@@ -35,7 +35,7 @@
 } from '../../shared/gr-dropdown-list/gr-dropdown-list';
 import {queryAndAssert} from '../../../test/test-utils';
 import {fire} from '../../../utils/event-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 type RevIdToRevisionInfo = {
   [revisionId: string]: RevisionInfo | EditRevisionInfo;
diff --git a/polygerrit-ui/app/elements/documentation/gr-documentation-search/gr-documentation-search_test.ts b/polygerrit-ui/app/elements/documentation/gr-documentation-search/gr-documentation-search_test.ts
index 221886a..7e6b98d 100644
--- a/polygerrit-ui/app/elements/documentation/gr-documentation-search/gr-documentation-search_test.ts
+++ b/polygerrit-ui/app/elements/documentation/gr-documentation-search/gr-documentation-search_test.ts
@@ -9,7 +9,7 @@
 import {page} from '../../../utils/page-wrapper-utils';
 import {queryAndAssert, stubRestApi} from '../../../test/test-utils';
 import {DocResult} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 function documentationGenerator(counter: number) {
   return {
diff --git a/polygerrit-ui/app/elements/edit/gr-default-editor/gr-default-editor_test.ts b/polygerrit-ui/app/elements/edit/gr-default-editor/gr-default-editor_test.ts
index 39c74ee..721a280 100644
--- a/polygerrit-ui/app/elements/edit/gr-default-editor/gr-default-editor_test.ts
+++ b/polygerrit-ui/app/elements/edit/gr-default-editor/gr-default-editor_test.ts
@@ -7,7 +7,7 @@
 import './gr-default-editor';
 import {GrDefaultEditor} from './gr-default-editor';
 import {mockPromise, queryAndAssert} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-default-editor tests', () => {
   let element: GrDefaultEditor;
diff --git a/polygerrit-ui/app/elements/edit/gr-edit-controls/gr-edit-controls_test.ts b/polygerrit-ui/app/elements/edit/gr-edit-controls/gr-edit-controls_test.ts
index 7605e41..e884cca 100644
--- a/polygerrit-ui/app/elements/edit/gr-edit-controls/gr-edit-controls_test.ts
+++ b/polygerrit-ui/app/elements/edit/gr-edit-controls/gr-edit-controls_test.ts
@@ -19,7 +19,7 @@
 import {RepoName} from '../../../api/rest-api';
 import {queryAndAssert} from '../../../test/test-utils';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrButton} from '../../shared/gr-button/gr-button';
 import '../../shared/gr-dialog/gr-dialog';
 
diff --git a/polygerrit-ui/app/elements/edit/gr-edit-file-controls/gr-edit-file-controls_test.ts b/polygerrit-ui/app/elements/edit/gr-edit-file-controls/gr-edit-file-controls_test.ts
index 90b6d93..5fc183f 100644
--- a/polygerrit-ui/app/elements/edit/gr-edit-file-controls/gr-edit-file-controls_test.ts
+++ b/polygerrit-ui/app/elements/edit/gr-edit-file-controls/gr-edit-file-controls_test.ts
@@ -10,7 +10,7 @@
 import {queryAndAssert} from '../../../test/test-utils';
 import {GrDropdown} from '../../shared/gr-dropdown/gr-dropdown';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-edit-file-controls tests', () => {
   let element: GrEditFileControls;
diff --git a/polygerrit-ui/app/elements/edit/gr-editor-view/gr-editor-view_test.ts b/polygerrit-ui/app/elements/edit/gr-editor-view/gr-editor-view_test.ts
index 6bb1cd9..5cb8cd5 100644
--- a/polygerrit-ui/app/elements/edit/gr-editor-view/gr-editor-view_test.ts
+++ b/polygerrit-ui/app/elements/edit/gr-editor-view/gr-editor-view_test.ts
@@ -23,7 +23,7 @@
 import {GrEndpointDecorator} from '../../plugins/gr-endpoint-decorator/gr-endpoint-decorator';
 import {GrDefaultEditor} from '../gr-default-editor/gr-default-editor';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EventType} from '../../../types/events';
 
 suite('gr-editor-view tests', () => {
diff --git a/polygerrit-ui/app/elements/gr-app_test.ts b/polygerrit-ui/app/elements/gr-app_test.ts
index 6327ad2..b811af1 100644
--- a/polygerrit-ui/app/elements/gr-app_test.ts
+++ b/polygerrit-ui/app/elements/gr-app_test.ts
@@ -6,7 +6,7 @@
 import '../test/common-test-setup-karma';
 import './gr-app';
 import {getAppContext} from '../services/app-context';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {queryAndAssert, stubElement, stubRestApi} from '../test/test-utils';
 import {GrApp} from './gr-app';
 import {
diff --git a/polygerrit-ui/app/elements/plugins/gr-admin-api/gr-admin-api_test.ts b/polygerrit-ui/app/elements/plugins/gr-admin-api/gr-admin-api_test.ts
index d6cf768..32b599a 100644
--- a/polygerrit-ui/app/elements/plugins/gr-admin-api/gr-admin-api_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-admin-api/gr-admin-api_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {AdminPluginApi} from '../../../api/admin';
 import {PluginApi} from '../../../api/plugin';
 import '../../../test/common-test-setup-karma';
diff --git a/polygerrit-ui/app/elements/plugins/gr-attribute-helper/gr-attribute-helper_test.js b/polygerrit-ui/app/elements/plugins/gr-attribute-helper/gr-attribute-helper_test.js
index c17fc5d..2a88dae 100644
--- a/polygerrit-ui/app/elements/plugins/gr-attribute-helper/gr-attribute-helper_test.js
+++ b/polygerrit-ui/app/elements/plugins/gr-attribute-helper/gr-attribute-helper_test.js
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma.js';
 import {Polymer} from '@polymer/polymer/lib/legacy/polymer-fn.js';
 // eslint-disable-next-line import/named
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 Polymer({
   is: 'gr-attribute-helper-some-element',
diff --git a/polygerrit-ui/app/elements/plugins/gr-checks-api/gr-checks-api_test.ts b/polygerrit-ui/app/elements/plugins/gr-checks-api/gr-checks-api_test.ts
index c85b4db..552feda 100644
--- a/polygerrit-ui/app/elements/plugins/gr-checks-api/gr-checks-api_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-checks-api/gr-checks-api_test.ts
@@ -7,6 +7,7 @@
 import {getPluginLoader} from '../../shared/gr-js-api-interface/gr-plugin-loader';
 import {PluginApi} from '../../../api/plugin';
 import {ChecksPluginApi} from '../../../api/checks';
+import {assert} from '@open-wc/testing';
 
 suite('gr-settings-api tests', () => {
   let checksApi: ChecksPluginApi | undefined;
diff --git a/polygerrit-ui/app/elements/plugins/gr-dom-hooks/gr-dom-hooks_test.ts b/polygerrit-ui/app/elements/plugins/gr-dom-hooks/gr-dom-hooks_test.ts
index 6001622..4da3cdc 100644
--- a/polygerrit-ui/app/elements/plugins/gr-dom-hooks/gr-dom-hooks_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-dom-hooks/gr-dom-hooks_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {HookApi, PluginElement} from '../../../api/hook';
 import {PluginApi} from '../../../api/plugin';
 import '../../../test/common-test-setup-karma';
diff --git a/polygerrit-ui/app/elements/plugins/gr-endpoint-decorator/gr-endpoint-decorator_test.ts b/polygerrit-ui/app/elements/plugins/gr-endpoint-decorator/gr-endpoint-decorator_test.ts
index aba804c..8218ebb 100644
--- a/polygerrit-ui/app/elements/plugins/gr-endpoint-decorator/gr-endpoint-decorator_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-endpoint-decorator/gr-endpoint-decorator_test.ts
@@ -7,7 +7,7 @@
 import './gr-endpoint-decorator';
 import '../gr-endpoint-param/gr-endpoint-param';
 import '../gr-endpoint-slot/gr-endpoint-slot';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {
   mockPromise,
   queryAndAssert,
diff --git a/polygerrit-ui/app/elements/plugins/gr-event-helper/gr-event-helper_test.ts b/polygerrit-ui/app/elements/plugins/gr-event-helper/gr-event-helper_test.ts
index 8eb450a..80d8a52 100644
--- a/polygerrit-ui/app/elements/plugins/gr-event-helper/gr-event-helper_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-event-helper/gr-event-helper_test.ts
@@ -5,7 +5,7 @@
  */
 import '../../../test/common-test-setup-karma';
 // eslint-disable-next-line import/named
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {PluginApi} from '../../../api/plugin';
 import {EventHelperPluginApi} from '../../../api/event-helper';
 
diff --git a/polygerrit-ui/app/elements/plugins/gr-external-style/gr-external-style_test.ts b/polygerrit-ui/app/elements/plugins/gr-external-style/gr-external-style_test.ts
index 59475ed..545b2a2 100644
--- a/polygerrit-ui/app/elements/plugins/gr-external-style/gr-external-style_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-external-style/gr-external-style_test.ts
@@ -9,7 +9,7 @@
 import {GrExternalStyle} from './gr-external-style';
 import {getPluginLoader} from '../../shared/gr-js-api-interface/gr-plugin-loader';
 import {PluginApi} from '../../../api/plugin';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-external-style integration tests', () => {
   const TEST_URL = 'http://some.com/plugins/url.js';
diff --git a/polygerrit-ui/app/elements/plugins/gr-plugin-host/gr-plugin-host_test.ts b/polygerrit-ui/app/elements/plugins/gr-plugin-host/gr-plugin-host_test.ts
index 520af04..8b0ee3f 100644
--- a/polygerrit-ui/app/elements/plugins/gr-plugin-host/gr-plugin-host_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-plugin-host/gr-plugin-host_test.ts
@@ -7,7 +7,7 @@
 import './gr-plugin-host';
 import {getPluginLoader} from '../../shared/gr-js-api-interface/gr-plugin-loader';
 import {GrPluginHost} from './gr-plugin-host';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {SinonStub} from 'sinon';
 import {createServerInfo} from '../../../test/test-data-generators';
 
diff --git a/polygerrit-ui/app/elements/plugins/gr-popup-interface/gr-plugin-popup_test.ts b/polygerrit-ui/app/elements/plugins/gr-popup-interface/gr-plugin-popup_test.ts
index 4cf468f..e663e65 100644
--- a/polygerrit-ui/app/elements/plugins/gr-popup-interface/gr-plugin-popup_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-popup-interface/gr-plugin-popup_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import {stubElement} from '../../../test/test-utils';
 import './gr-plugin-popup';
diff --git a/polygerrit-ui/app/elements/plugins/gr-popup-interface/gr-popup-interface_test.ts b/polygerrit-ui/app/elements/plugins/gr-popup-interface/gr-popup-interface_test.ts
index 1bd581e..dae5e09 100644
--- a/polygerrit-ui/app/elements/plugins/gr-popup-interface/gr-popup-interface_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-popup-interface/gr-popup-interface_test.ts
@@ -11,7 +11,7 @@
 import {queryAndAssert} from '../../../test/test-utils';
 import {LitElement, html} from 'lit';
 import {customElement} from 'lit/decorators.js';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 
 @customElement('gr-user-test-popup')
 class GrUserTestPopupElement extends LitElement {
diff --git a/polygerrit-ui/app/elements/settings/gr-account-info/gr-account-info_test.ts b/polygerrit-ui/app/elements/settings/gr-account-info/gr-account-info_test.ts
index 50c87b4..498f20c 100644
--- a/polygerrit-ui/app/elements/settings/gr-account-info/gr-account-info_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-account-info/gr-account-info_test.ts
@@ -19,7 +19,7 @@
 import {SinonStubbedMember} from 'sinon';
 import {RestApiService} from '../../../services/gr-rest-api/gr-rest-api';
 import {EditableAccountField} from '../../../api/rest-api';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-account-info tests', () => {
   let element!: GrAccountInfo;
diff --git a/polygerrit-ui/app/elements/settings/gr-agreements-list/gr-agreements-list_test.ts b/polygerrit-ui/app/elements/settings/gr-agreements-list/gr-agreements-list_test.ts
index 003e29d..e9c016b 100644
--- a/polygerrit-ui/app/elements/settings/gr-agreements-list/gr-agreements-list_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-agreements-list/gr-agreements-list_test.ts
@@ -8,7 +8,7 @@
 import {stubRestApi} from '../../../test/test-utils';
 import {GrAgreementsList} from './gr-agreements-list';
 import {ContributorAgreementInfo} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-agreements-list tests', () => {
   let element: GrAgreementsList;
diff --git a/polygerrit-ui/app/elements/settings/gr-change-table-editor/gr-change-table-editor_test.ts b/polygerrit-ui/app/elements/settings/gr-change-table-editor/gr-change-table-editor_test.ts
index 14a27c9..2baf81c 100644
--- a/polygerrit-ui/app/elements/settings/gr-change-table-editor/gr-change-table-editor_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-change-table-editor/gr-change-table-editor_test.ts
@@ -8,7 +8,7 @@
 import {GrChangeTableEditor} from './gr-change-table-editor';
 import {queryAndAssert} from '../../../test/test-utils';
 import {createServerInfo} from '../../../test/test-data-generators';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {ColumnNames} from '../../../constants/constants';
 
 suite('gr-change-table-editor tests', () => {
diff --git a/polygerrit-ui/app/elements/settings/gr-cla-view/gr-cla-view_test.ts b/polygerrit-ui/app/elements/settings/gr-cla-view/gr-cla-view_test.ts
index 2111277..7a5df95 100644
--- a/polygerrit-ui/app/elements/settings/gr-cla-view/gr-cla-view_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-cla-view/gr-cla-view_test.ts
@@ -16,7 +16,7 @@
 } from '../../../types/common';
 import {AuthType} from '../../../constants/constants';
 import {createServerInfo} from '../../../test/test-data-generators';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-cla-view tests', () => {
   let element: GrClaView;
diff --git a/polygerrit-ui/app/elements/settings/gr-edit-preferences/gr-edit-preferences_test.ts b/polygerrit-ui/app/elements/settings/gr-edit-preferences/gr-edit-preferences_test.ts
index 6f16273..443bc21 100644
--- a/polygerrit-ui/app/elements/settings/gr-edit-preferences/gr-edit-preferences_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-edit-preferences/gr-edit-preferences_test.ts
@@ -10,7 +10,7 @@
 import {EditPreferencesInfo, ParsedJSON} from '../../../types/common';
 import {IronInputElement} from '@polymer/iron-input';
 import {createDefaultEditPrefs} from '../../../constants/constants';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-edit-preferences tests', () => {
   let element: GrEditPreferences;
diff --git a/polygerrit-ui/app/elements/settings/gr-email-editor/gr-email-editor_test.ts b/polygerrit-ui/app/elements/settings/gr-email-editor/gr-email-editor_test.ts
index e8b0f79..640e7f8 100644
--- a/polygerrit-ui/app/elements/settings/gr-email-editor/gr-email-editor_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-email-editor/gr-email-editor_test.ts
@@ -7,7 +7,7 @@
 import './gr-email-editor';
 import {GrEmailEditor} from './gr-email-editor';
 import {spyRestApi, stubRestApi} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-email-editor tests', () => {
   let element: GrEmailEditor;
diff --git a/polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor_test.ts b/polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor_test.ts
index b41169f..f55580d 100644
--- a/polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor_test.ts
@@ -19,7 +19,7 @@
   OpenPgpUserIds,
 } from '../../../api/rest-api';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-gpg-editor tests', () => {
   let element: GrGpgEditor;
diff --git a/polygerrit-ui/app/elements/settings/gr-group-list/gr-group-list_test.ts b/polygerrit-ui/app/elements/settings/gr-group-list/gr-group-list_test.ts
index 2e26b1b..db00211 100644
--- a/polygerrit-ui/app/elements/settings/gr-group-list/gr-group-list_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-group-list/gr-group-list_test.ts
@@ -9,7 +9,7 @@
 import {GerritNav} from '../../core/gr-navigation/gr-navigation';
 import {GroupId, GroupInfo, GroupName} from '../../../types/common';
 import {stubRestApi} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-group-list tests', () => {
   let element: GrGroupList;
diff --git a/polygerrit-ui/app/elements/settings/gr-http-password/gr-http-password_test.ts b/polygerrit-ui/app/elements/settings/gr-http-password/gr-http-password_test.ts
index 5c1fa7e..3dc0c65 100644
--- a/polygerrit-ui/app/elements/settings/gr-http-password/gr-http-password_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-http-password/gr-http-password_test.ts
@@ -15,7 +15,7 @@
 import {AccountDetailInfo, ServerInfo} from '../../../types/common';
 import {queryAndAssert} from '../../../test/test-utils';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-http-password tests', () => {
   let element: GrHttpPassword;
diff --git a/polygerrit-ui/app/elements/settings/gr-identities/gr-identities_test.ts b/polygerrit-ui/app/elements/settings/gr-identities/gr-identities_test.ts
index 77af8a0..bdb4e22 100644
--- a/polygerrit-ui/app/elements/settings/gr-identities/gr-identities_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-identities/gr-identities_test.ts
@@ -12,7 +12,7 @@
 import {createServerInfo} from '../../../test/test-data-generators';
 import {queryAll, queryAndAssert} from '../../../test/test-utils';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-identities tests', () => {
   let element: GrIdentities;
diff --git a/polygerrit-ui/app/elements/settings/gr-menu-editor/gr-menu-editor_test.ts b/polygerrit-ui/app/elements/settings/gr-menu-editor/gr-menu-editor_test.ts
index 2bcb38f..7499545 100644
--- a/polygerrit-ui/app/elements/settings/gr-menu-editor/gr-menu-editor_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-menu-editor/gr-menu-editor_test.ts
@@ -11,7 +11,7 @@
 import {PaperButtonElement} from '@polymer/paper-button';
 import {TopMenuItemInfo} from '../../../types/common';
 import {GrButton} from '../../shared/gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {createDefaultPreferences} from '../../../constants/constants';
 
 suite('gr-menu-editor tests', () => {
diff --git a/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_test.ts b/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_test.ts
index c8ffea5..8718fbb 100644
--- a/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_test.ts
@@ -13,7 +13,7 @@
   createAccountWithId,
   createServerInfo,
 } from '../../../test/test-data-generators';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrButton} from '../../shared/gr-button/gr-button';
 
 suite('gr-registration-dialog tests', () => {
diff --git a/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view_test.ts b/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view_test.ts
index 57b0dab..d718a07 100644
--- a/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view_test.ts
@@ -34,7 +34,7 @@
 } from '../../../test/test-data-generators';
 import {GrSelect} from '../../shared/gr-select/gr-select';
 import {AppElementSettingsParam} from '../../gr-app-types';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EventType} from '../../../types/events';
 
 suite('gr-settings-view tests', () => {
diff --git a/polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor_test.ts b/polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor_test.ts
index 4f7f8b6..77b5d13 100644
--- a/polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor_test.ts
@@ -10,7 +10,7 @@
 import {SshKeyInfo} from '../../../types/common';
 import {GrButton} from '../../shared/gr-button/gr-button';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-ssh-editor tests', () => {
   let element: GrSshEditor;
diff --git a/polygerrit-ui/app/elements/settings/gr-watched-projects-editor/gr-watched-projects-editor_test.ts b/polygerrit-ui/app/elements/settings/gr-watched-projects-editor/gr-watched-projects-editor_test.ts
index 60dcb44..19d295f 100644
--- a/polygerrit-ui/app/elements/settings/gr-watched-projects-editor/gr-watched-projects-editor_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-watched-projects-editor/gr-watched-projects-editor_test.ts
@@ -12,7 +12,7 @@
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {IronInputElement} from '@polymer/iron-input';
 import {assertIsDefined} from '../../../utils/common-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-watched-projects-editor tests', () => {
   let element: GrWatchedProjectsEditor;
diff --git a/polygerrit-ui/app/elements/shared/gr-account-chip/gr-account-chip_test.ts b/polygerrit-ui/app/elements/shared/gr-account-chip/gr-account-chip_test.ts
index f0c556e..f551bd0 100644
--- a/polygerrit-ui/app/elements/shared/gr-account-chip/gr-account-chip_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-account-chip/gr-account-chip_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-account-chip';
 import {GrAccountChip} from './gr-account-chip';
diff --git a/polygerrit-ui/app/elements/shared/gr-account-entry/gr-account-entry_test.ts b/polygerrit-ui/app/elements/shared/gr-account-entry/gr-account-entry_test.ts
index 4fd9449..78d45eb 100644
--- a/polygerrit-ui/app/elements/shared/gr-account-entry/gr-account-entry_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-account-entry/gr-account-entry_test.ts
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-account-entry';
 import {GrAccountEntry} from './gr-account-entry';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {queryAndAssert, waitUntil} from '../../../test/test-utils';
 import {GrAutocomplete} from '../gr-autocomplete/gr-autocomplete';
 import {PaperInputElement} from '@polymer/paper-input/paper-input';
diff --git a/polygerrit-ui/app/elements/shared/gr-account-label/gr-account-label_test.ts b/polygerrit-ui/app/elements/shared/gr-account-label/gr-account-label_test.ts
index 9e0bf46..559395c 100644
--- a/polygerrit-ui/app/elements/shared/gr-account-label/gr-account-label_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-account-label/gr-account-label_test.ts
@@ -21,7 +21,7 @@
   createServerInfo,
 } from '../../../test/test-data-generators';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-account-label tests', () => {
   let element: GrAccountLabel;
diff --git a/polygerrit-ui/app/elements/shared/gr-account-list/gr-account-list_test.ts b/polygerrit-ui/app/elements/shared/gr-account-list/gr-account-list_test.ts
index 17d93ac..94fb5c7 100644
--- a/polygerrit-ui/app/elements/shared/gr-account-list/gr-account-list_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-account-list/gr-account-list_test.ts
@@ -30,7 +30,7 @@
 import {GrAccountEntry} from '../gr-account-entry/gr-account-entry';
 import {createChange} from '../../../test/test-data-generators';
 import {ReviewerState} from '../../../api/rest-api';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EventType} from '../../../types/events';
 
 class MockSuggestionsProvider implements ReviewerSuggestionsProvider {
diff --git a/polygerrit-ui/app/elements/shared/gr-alert/gr-alert_test.ts b/polygerrit-ui/app/elements/shared/gr-alert/gr-alert_test.ts
index 173d154..799fb81 100644
--- a/polygerrit-ui/app/elements/shared/gr-alert/gr-alert_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-alert/gr-alert_test.ts
@@ -7,6 +7,7 @@
 import './gr-alert';
 import {GrAlert} from './gr-alert';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
+import {assert} from '@open-wc/testing';
 
 suite('gr-alert tests', () => {
   let element: GrAlert;
diff --git a/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown_test.ts b/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown_test.ts
index 49150f0..cad3ff0 100644
--- a/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown_test.ts
@@ -9,7 +9,7 @@
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {queryAll, queryAndAssert} from '../../../test/test-utils';
 import {assertIsDefined} from '../../../utils/common-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-autocomplete-dropdown', () => {
   let element: GrAutocompleteDropdown;
diff --git a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete_test.ts b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete_test.ts
index e41eea3..2351c5e 100644
--- a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete_test.ts
@@ -10,7 +10,7 @@
 import {queryAndAssert, waitUntil} from '../../../test/test-utils';
 import {GrAutocompleteDropdown} from '../gr-autocomplete-dropdown/gr-autocomplete-dropdown';
 import {PaperInputElement} from '@polymer/paper-input/paper-input';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {Key} from '../../../utils/dom-util';
 
 suite('gr-autocomplete tests', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar-stack_test.ts b/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar-stack_test.ts
index 5a478f8..5365cc7 100644
--- a/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar-stack_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar-stack_test.ts
@@ -9,7 +9,7 @@
   createAccountWithId,
   createServerInfo,
 } from '../../../test/test-data-generators';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {stubRestApi} from '../../../test/test-utils';
 import {LitElement} from 'lit';
 
diff --git a/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.ts b/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.ts
index 43b5402..01a8247 100644
--- a/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.ts
@@ -12,7 +12,7 @@
   createAccountWithId,
   createServerInfo,
 } from '../../../test/test-data-generators';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {isVisible, stubRestApi} from '../../../test/test-utils';
 
 suite('gr-avatar tests', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.ts b/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.ts
index 35db0bc..8fee549 100644
--- a/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-button/gr-button_test.ts
@@ -7,7 +7,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-button';
 import {addListener} from '@polymer/polymer/lib/utils/gestures';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrButton} from './gr-button';
 import {pressKey, queryAndAssert} from '../../../test/test-utils';
 import {PaperButtonElement} from '@polymer/paper-button';
diff --git a/polygerrit-ui/app/elements/shared/gr-change-star/gr-change-star_test.ts b/polygerrit-ui/app/elements/shared/gr-change-star/gr-change-star_test.ts
index 5592f5f..8b95713 100644
--- a/polygerrit-ui/app/elements/shared/gr-change-star/gr-change-star_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-change-star/gr-change-star_test.ts
@@ -9,7 +9,7 @@
 import './gr-change-star';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {createChange} from '../../../test/test-data-generators';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-change-star tests', () => {
   let element: GrChangeStar;
diff --git a/polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status_test.ts b/polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status_test.ts
index d93fea0..5c4a584 100644
--- a/polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status_test.ts
@@ -9,7 +9,7 @@
 import {ChangeStates, GrChangeStatus, WIP_TOOLTIP} from './gr-change-status';
 import {GerritNav} from '../../core/gr-navigation/gr-navigation';
 import {MERGE_CONFLICT_TOOLTIP} from './gr-change-status';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {queryAndAssert} from '../../../test/test-utils';
 
 const PRIVATE_TOOLTIP =
diff --git a/polygerrit-ui/app/elements/shared/gr-comment-thread/gr-comment-thread_test.ts b/polygerrit-ui/app/elements/shared/gr-comment-thread/gr-comment-thread_test.ts
index 7be39e7..d02f97c 100644
--- a/polygerrit-ui/app/elements/shared/gr-comment-thread/gr-comment-thread_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-comment-thread/gr-comment-thread_test.ts
@@ -27,7 +27,7 @@
 } from '../../../test/test-data-generators';
 import {tap} from '@polymer/iron-test-helpers/mock-interactions';
 import {SinonStub} from 'sinon';
-import {fixture, html, waitUntil} from '@open-wc/testing';
+import {fixture, html, waitUntil, assert} from '@open-wc/testing';
 
 const c1 = {
   author: {name: 'Kermit'},
diff --git a/polygerrit-ui/app/elements/shared/gr-comment/gr-comment_test.ts b/polygerrit-ui/app/elements/shared/gr-comment/gr-comment_test.ts
index 839085e..0019901 100644
--- a/polygerrit-ui/app/elements/shared/gr-comment/gr-comment_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-comment/gr-comment_test.ts
@@ -42,7 +42,7 @@
 import {assertIsDefined} from '../../../utils/common-util';
 import {Modifier} from '../../../utils/dom-util';
 import {SinonStub} from 'sinon';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-comment tests', () => {
   let element: GrComment;
diff --git a/polygerrit-ui/app/elements/shared/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog_test.ts b/polygerrit-ui/app/elements/shared/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog_test.ts
index 9008c86..2b3b225 100644
--- a/polygerrit-ui/app/elements/shared/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrConfirmDeleteCommentDialog} from './gr-confirm-delete-comment-dialog';
 import './gr-confirm-delete-comment-dialog';
 
diff --git a/polygerrit-ui/app/elements/shared/gr-copy-clipboard/gr-copy-clipboard_test.ts b/polygerrit-ui/app/elements/shared/gr-copy-clipboard/gr-copy-clipboard_test.ts
index 6c938b1..d3bffab 100644
--- a/polygerrit-ui/app/elements/shared/gr-copy-clipboard/gr-copy-clipboard_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-copy-clipboard/gr-copy-clipboard_test.ts
@@ -8,7 +8,7 @@
 import {GrCopyClipboard} from './gr-copy-clipboard';
 import {queryAndAssert} from '../../../test/test-utils';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-copy-clipboard tests', () => {
   let element: GrCopyClipboard;
diff --git a/polygerrit-ui/app/elements/shared/gr-cursor-manager/gr-cursor-manager_test.js b/polygerrit-ui/app/elements/shared/gr-cursor-manager/gr-cursor-manager_test.js
index 0e6c954..e09f8f7 100644
--- a/polygerrit-ui/app/elements/shared/gr-cursor-manager/gr-cursor-manager_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-cursor-manager/gr-cursor-manager_test.js
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma.js';
 import './gr-cursor-manager.js';
 // eslint-disable-next-line import/named
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {AbortStop, CursorMoveResult} from '../../../api/core.js';
 import {GrCursorManager} from './gr-cursor-manager.js';
 
diff --git a/polygerrit-ui/app/elements/shared/gr-date-formatter/gr-date-formatter_test.ts b/polygerrit-ui/app/elements/shared/gr-date-formatter/gr-date-formatter_test.ts
index 5b1a896..a300fbb 100644
--- a/polygerrit-ui/app/elements/shared/gr-date-formatter/gr-date-formatter_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-date-formatter/gr-date-formatter_test.ts
@@ -7,7 +7,7 @@
 import './gr-date-formatter';
 import {GrDateFormatter} from './gr-date-formatter';
 import {parseDate} from '../../../utils/date-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {query, queryAndAssert, stubRestApi} from '../../../test/test-utils';
 import {GrTooltipContent} from '../gr-tooltip-content/gr-tooltip-content';
 import {Timestamp} from '../../../api/rest-api';
diff --git a/polygerrit-ui/app/elements/shared/gr-dialog/gr-dialog_test.ts b/polygerrit-ui/app/elements/shared/gr-dialog/gr-dialog_test.ts
index 1fa0f1c..bb72d62 100644
--- a/polygerrit-ui/app/elements/shared/gr-dialog/gr-dialog_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-dialog/gr-dialog_test.ts
@@ -8,7 +8,7 @@
 import './gr-dialog';
 import {GrDialog} from './gr-dialog';
 import {isHidden, queryAndAssert} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-dialog tests', () => {
   let element: GrDialog;
diff --git a/polygerrit-ui/app/elements/shared/gr-diff-preferences/gr-diff-preferences_test.ts b/polygerrit-ui/app/elements/shared/gr-diff-preferences/gr-diff-preferences_test.ts
index bf439df..da4fa13 100644
--- a/polygerrit-ui/app/elements/shared/gr-diff-preferences/gr-diff-preferences_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-diff-preferences/gr-diff-preferences_test.ts
@@ -12,7 +12,7 @@
 import {IronInputElement} from '@polymer/iron-input';
 import {GrSelect} from '../gr-select/gr-select';
 import {ParsedJSON} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-diff-preferences tests', () => {
   let element: GrDiffPreferences;
diff --git a/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands_test.ts b/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands_test.ts
index afcccc2..6d944ee 100644
--- a/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands_test.ts
@@ -17,7 +17,7 @@
 import {GrShellCommand} from '../gr-shell-command/gr-shell-command';
 import {createDefaultPreferences} from '../../../constants/constants';
 import {PaperTabsElement} from '@polymer/paper-tabs/paper-tabs';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-download-commands', () => {
   let element: GrDownloadCommands;
diff --git a/polygerrit-ui/app/elements/shared/gr-dropdown-list/gr-dropdown-list_test.ts b/polygerrit-ui/app/elements/shared/gr-dropdown-list/gr-dropdown-list_test.ts
index 82337f5..4dcb037 100644
--- a/polygerrit-ui/app/elements/shared/gr-dropdown-list/gr-dropdown-list_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-dropdown-list/gr-dropdown-list_test.ts
@@ -11,7 +11,7 @@
 import {PaperListboxElement} from '@polymer/paper-listbox';
 import {Timestamp} from '../../../types/common';
 import {assertIsDefined} from '../../../utils/common-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-dropdown-list tests', () => {
   let element: GrDropdownList;
diff --git a/polygerrit-ui/app/elements/shared/gr-dropdown/gr-dropdown_test.ts b/polygerrit-ui/app/elements/shared/gr-dropdown/gr-dropdown_test.ts
index bb9b620..2bf442b 100644
--- a/polygerrit-ui/app/elements/shared/gr-dropdown/gr-dropdown_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-dropdown/gr-dropdown_test.ts
@@ -10,7 +10,7 @@
 import {queryAll, queryAndAssert} from '../../../test/test-utils';
 import {GrTooltipContent} from '../gr-tooltip-content/gr-tooltip-content';
 import {assertIsDefined} from '../../../utils/common-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-dropdown tests', () => {
   let element: GrDropdown;
diff --git a/polygerrit-ui/app/elements/shared/gr-editable-content/gr-editable-content_test.ts b/polygerrit-ui/app/elements/shared/gr-editable-content/gr-editable-content_test.ts
index 404c80e..695872b 100644
--- a/polygerrit-ui/app/elements/shared/gr-editable-content/gr-editable-content_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-editable-content/gr-editable-content_test.ts
@@ -9,7 +9,7 @@
 import {query, queryAndAssert, stubStorage} from '../../../test/test-utils';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {GrButton} from '../gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EventType} from '../../../types/events';
 
 suite('gr-editable-content tests', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-editable-label/gr-editable-label_test.ts b/polygerrit-ui/app/elements/shared/gr-editable-label/gr-editable-label_test.ts
index e0526bf..dfbcf58 100644
--- a/polygerrit-ui/app/elements/shared/gr-editable-label/gr-editable-label_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-editable-label/gr-editable-label_test.ts
@@ -10,7 +10,7 @@
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {PaperInputElement} from '@polymer/paper-input/paper-input';
 import {GrButton} from '../gr-button/gr-button';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {IronDropdownElement} from '@polymer/iron-dropdown';
 import {
   AutocompleteSuggestion,
diff --git a/polygerrit-ui/app/elements/shared/gr-file-status/gr-file-status_test.ts b/polygerrit-ui/app/elements/shared/gr-file-status/gr-file-status_test.ts
index f6624a9..7acba59 100644
--- a/polygerrit-ui/app/elements/shared/gr-file-status/gr-file-status_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-file-status/gr-file-status_test.ts
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-file-status';
 import {GrFileStatus} from './gr-file-status';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {FileInfoStatus} from '../../../api/rest-api';
 
 suite('gr-file-status tests', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text_test.ts b/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text_test.ts
index aaff897..30b8ca8 100644
--- a/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text_test.ts
@@ -3,7 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {KnownExperimentId} from '../../../services/flags/flags';
 import '../../../test/common-test-setup-karma';
 import {stubFlags} from '../../../test/test-utils';
diff --git a/polygerrit-ui/app/elements/shared/gr-hovercard-account/gr-hovercard-account_test.ts b/polygerrit-ui/app/elements/shared/gr-hovercard-account/gr-hovercard-account_test.ts
index a5053ad..20e9675 100644
--- a/polygerrit-ui/app/elements/shared/gr-hovercard-account/gr-hovercard-account_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-hovercard-account/gr-hovercard-account_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import './gr-hovercard-account';
 import {GrHovercardAccount} from './gr-hovercard-account';
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-annotation-actions-js-api_test.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-annotation-actions-js-api_test.js
index efaeb73..2b6dd2b 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-annotation-actions-js-api_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-annotation-actions-js-api_test.js
@@ -5,6 +5,7 @@
  */
 import '../../../test/common-test-setup-karma.js';
 import '../../change/gr-change-actions/gr-change-actions.js';
+import {assert} from '@open-wc/testing';
 
 suite('gr-annotation-actions-js-api tests', () => {
   let annotationActions;
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils_test.ts b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils_test.ts
index 289df9d..5cdf365 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-api-utils_test.ts
@@ -6,6 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-js-api-interface';
 import {getPluginNameFromUrl} from './gr-api-utils';
+import {assert} from '@open-wc/testing';
 
 suite('gr-api-utils tests', () => {
   suite('test getPluginNameFromUrl', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-change-actions-js-api_test.ts b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-change-actions-js-api_test.ts
index 7f26cbb..9a5ce08 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-change-actions-js-api_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-change-actions-js-api_test.ts
@@ -13,7 +13,7 @@
 } from '../../../test/test-utils';
 import {getPluginLoader} from './gr-plugin-loader';
 import {GrChangeActions} from '../../change/gr-change-actions/gr-change-actions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {PluginApi} from '../../../api/plugin';
 import {
   ActionType,
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-change-reply-js-api_test.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-change-reply-js-api_test.js
index d68ac6d..471474d 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-change-reply-js-api_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-change-reply-js-api_test.js
@@ -7,7 +7,7 @@
 import '../../change/gr-reply-dialog/gr-reply-dialog.js';
 import {stubRestApi} from '../../../test/test-utils.js';
 // eslint-disable-next-line import/named
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-change-reply-js-api tests', () => {
   let element;
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit_test.ts b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit_test.ts
index daeed3a..1eca121 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-gerrit_test.ts
@@ -15,6 +15,7 @@
 import {GrJsApiInterface} from './gr-js-api-interface-element';
 import {SinonFakeTimers} from 'sinon';
 import {Timestamp} from '../../../api/rest-api';
+import {assert} from '@open-wc/testing';
 
 suite('gr-gerrit tests', () => {
   let element: GrJsApiInterface;
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface_test.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface_test.js
index a57273c..784f8f8 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface_test.js
@@ -12,6 +12,7 @@
 import {stubBaseUrl} from '../../../test/test-utils.js';
 import {stubRestApi} from '../../../test/test-utils.js';
 import {getAppContext} from '../../../services/app-context.js';
+import {assert} from '@open-wc/testing';
 
 suite('GrJsApiInterface tests', () => {
   let element;
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-action-context_test.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-action-context_test.js
index 13b1921..1910bd1 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-action-context_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-action-context_test.js
@@ -8,6 +8,7 @@
 import {GrPluginActionContext} from './gr-plugin-action-context.js';
 import {addListenerForTest} from '../../../test/test-utils.js';
 import {EventType} from '../../../types/events.js';
+import {assert} from '@open-wc/testing';
 
 suite('gr-plugin-action-context tests', () => {
   let instance;
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-endpoints_test.ts b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-endpoints_test.ts
index a1421ab..c2e923a 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-endpoints_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-endpoints_test.ts
@@ -9,6 +9,7 @@
 import {GrPluginEndpoints} from './gr-plugin-endpoints';
 import {PluginApi} from '../../../api/plugin';
 import {HookApi, HookCallback, PluginElement} from '../../../api/hook';
+import {assert} from '@open-wc/testing';
 
 export class MockHook<T extends PluginElement> implements HookApi<T> {
   handleInstanceDetached(_: T) {}
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-loader_test.ts b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-loader_test.ts
index 0b30e84..cdac08e 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-loader_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-loader_test.ts
@@ -12,6 +12,7 @@
 import {SinonFakeTimers} from 'sinon';
 import {Timestamp} from '../../../api/rest-api';
 import {EventType} from '../../../types/events';
+import {assert} from '@open-wc/testing';
 
 suite('gr-plugin-loader tests', () => {
   let plugin: PluginApi;
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-rest-api_test.js b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-rest-api_test.js
index d74ee35..54cd72b 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-rest-api_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-rest-api_test.js
@@ -7,6 +7,7 @@
 import './gr-js-api-interface.js';
 import {GrPluginRestApi} from './gr-plugin-rest-api.js';
 import {stubRestApi} from '../../../test/test-utils.js';
+import {assert} from '@open-wc/testing';
 
 suite('gr-plugin-rest-api tests', () => {
   let instance;
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-reporting-js-api_test.ts b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-reporting-js-api_test.ts
index 74e98ba..98e04a3 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-reporting-js-api_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-reporting-js-api_test.ts
@@ -10,6 +10,7 @@
 import {PluginApi} from '../../../api/plugin.js';
 import {ReportingService} from '../../../services/gr-reporting/gr-reporting.js';
 import {ReportingPluginApi} from '../../../api/reporting.js';
+import {assert} from '@open-wc/testing';
 
 suite('gr-reporting-js-api tests', () => {
   let plugin: PluginApi;
diff --git a/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info_test.ts b/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info_test.ts
index a7681f3..d503ee1 100644
--- a/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info_test.ts
@@ -20,7 +20,7 @@
   createParsedChange,
 } from '../../../test/test-data-generators';
 import {ApprovalInfo, LabelInfo} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-label-info tests', () => {
   let element: GrLabelInfo;
diff --git a/polygerrit-ui/app/elements/shared/gr-labeled-autocomplete/gr-labeled-autocomplete_test.ts b/polygerrit-ui/app/elements/shared/gr-labeled-autocomplete/gr-labeled-autocomplete_test.ts
index c55411c..8513b0e 100644
--- a/polygerrit-ui/app/elements/shared/gr-labeled-autocomplete/gr-labeled-autocomplete_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-labeled-autocomplete/gr-labeled-autocomplete_test.ts
@@ -7,7 +7,7 @@
 import './gr-labeled-autocomplete';
 import {GrLabeledAutocomplete} from './gr-labeled-autocomplete';
 import {assertIsDefined} from '../../../utils/common-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-labeled-autocomplete tests', () => {
   let element: GrLabeledAutocomplete;
diff --git a/polygerrit-ui/app/elements/shared/gr-lib-loader/gr-lib-loader_test.ts b/polygerrit-ui/app/elements/shared/gr-lib-loader/gr-lib-loader_test.ts
index 3617eef..8589214 100644
--- a/polygerrit-ui/app/elements/shared/gr-lib-loader/gr-lib-loader_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-lib-loader/gr-lib-loader_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import './gr-lib-loader';
 import {GrLibLoader} from './gr-lib-loader';
diff --git a/polygerrit-ui/app/elements/shared/gr-limited-text/gr-limited-text_test.ts b/polygerrit-ui/app/elements/shared/gr-limited-text/gr-limited-text_test.ts
index 8cefafd9..a17359a 100644
--- a/polygerrit-ui/app/elements/shared/gr-limited-text/gr-limited-text_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-limited-text/gr-limited-text_test.ts
@@ -8,7 +8,7 @@
 import {GrTooltipContent} from '../gr-tooltip-content/gr-tooltip-content';
 import './gr-limited-text';
 import {GrLimitedText} from './gr-limited-text';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-limited-text tests', () => {
   let element: GrLimitedText;
diff --git a/polygerrit-ui/app/elements/shared/gr-linked-chip/gr-linked-chip_test.ts b/polygerrit-ui/app/elements/shared/gr-linked-chip/gr-linked-chip_test.ts
index b9a055a..7bc977c 100644
--- a/polygerrit-ui/app/elements/shared/gr-linked-chip/gr-linked-chip_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-linked-chip/gr-linked-chip_test.ts
@@ -8,7 +8,7 @@
 import {GrLinkedChip} from './gr-linked-chip';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {queryAndAssert} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-linked-chip tests', () => {
   let element: GrLinkedChip;
diff --git a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.ts b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.ts
index 563fc57..da5c045 100644
--- a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.ts
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-linked-text';
 import {GerritNav} from '../../core/gr-navigation/gr-navigation';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrLinkedText} from './gr-linked-text';
 import {CommentLinks} from '../../../types/common';
 import {queryAndAssert} from '../../../test/test-utils';
diff --git a/polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view_test.ts b/polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view_test.ts
index 39efb54..0126cd7 100644
--- a/polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view_test.ts
@@ -10,7 +10,7 @@
 import {queryAndAssert, stubBaseUrl} from '../../../test/test-utils';
 import {GrButton} from '../gr-button/gr-button';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-list-view tests', () => {
   let element: GrListView;
diff --git a/polygerrit-ui/app/elements/shared/gr-overlay/gr-overlay_test.ts b/polygerrit-ui/app/elements/shared/gr-overlay/gr-overlay_test.ts
index 2c5ebfb..0140d57 100644
--- a/polygerrit-ui/app/elements/shared/gr-overlay/gr-overlay_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-overlay/gr-overlay_test.ts
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-overlay';
 import {GrOverlay} from './gr-overlay';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-overlay tests', () => {
   let element: GrOverlay;
diff --git a/polygerrit-ui/app/elements/shared/gr-page-nav/gr-page-nav_test.ts b/polygerrit-ui/app/elements/shared/gr-page-nav/gr-page-nav_test.ts
index 7c331b8..7223822 100644
--- a/polygerrit-ui/app/elements/shared/gr-page-nav/gr-page-nav_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-page-nav/gr-page-nav_test.ts
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-page-nav';
 import {GrPageNav} from './gr-page-nav';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {queryAndAssert} from '../../../test/test-utils';
 
 suite('gr-page-nav tests', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-repo-branch-picker/gr-repo-branch-picker_test.ts b/polygerrit-ui/app/elements/shared/gr-repo-branch-picker/gr-repo-branch-picker_test.ts
index aa18301..636cec2 100644
--- a/polygerrit-ui/app/elements/shared/gr-repo-branch-picker/gr-repo-branch-picker_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-repo-branch-picker/gr-repo-branch-picker_test.ts
@@ -8,7 +8,7 @@
 import {GrRepoBranchPicker} from './gr-repo-branch-picker';
 import {stubRestApi} from '../../../test/test-utils';
 import {GitRef, ProjectInfoWithName, RepoName} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-repo-branch-picker tests', () => {
   let element: GrRepoBranchPicker;
diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-etag-decorator_test.ts b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-etag-decorator_test.ts
index 8990e15..4ec7f65 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-etag-decorator_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-etag-decorator_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import {GrEtagDecorator} from './gr-etag-decorator';
 
diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-apis/gr-rest-api-helper_test.ts b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-apis/gr-rest-api-helper_test.ts
index 2d68372..b6e7098 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-apis/gr-rest-api-helper_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-apis/gr-rest-api-helper_test.ts
@@ -16,6 +16,7 @@
 import {ParsedJSON} from '../../../../types/common';
 import {HttpMethod} from '../../../../api/rest-api';
 import {SinonFakeTimers} from 'sinon';
+import {assert} from '@open-wc/testing';
 
 function makeParsedJSON<T>(val: T): ParsedJSON {
   return val as unknown as ParsedJSON;
diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-reviewer-updates-parser_test.js b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-reviewer-updates-parser_test.js
index 1a7548c..98a96ad 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-reviewer-updates-parser_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-reviewer-updates-parser_test.js
@@ -6,6 +6,7 @@
 import '../../../test/common-test-setup-karma.js';
 import {GrReviewerUpdatesParser} from './gr-reviewer-updates-parser.js';
 import {parseDate} from '../../../utils/date-util.js';
+import {assert} from '@open-wc/testing';
 
 suite('gr-reviewer-updates-parser tests', () => {
   let instance;
diff --git a/polygerrit-ui/app/elements/shared/gr-select/gr-select_test.ts b/polygerrit-ui/app/elements/shared/gr-select/gr-select_test.ts
index 99988c2..759b5bc 100644
--- a/polygerrit-ui/app/elements/shared/gr-select/gr-select_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-select/gr-select_test.ts
@@ -5,7 +5,7 @@
  */
 import '../../../test/common-test-setup-karma';
 import './gr-select';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrSelect} from './gr-select';
 
 suite('gr-select tests', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-shell-command/gr-shell-command_test.ts b/polygerrit-ui/app/elements/shared/gr-shell-command/gr-shell-command_test.ts
index 42376b1..da17a1d 100644
--- a/polygerrit-ui/app/elements/shared/gr-shell-command/gr-shell-command_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-shell-command/gr-shell-command_test.ts
@@ -8,7 +8,7 @@
 import {GrShellCommand} from './gr-shell-command';
 import {GrCopyClipboard} from '../gr-copy-clipboard/gr-copy-clipboard';
 import {queryAndAssert} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-shell-command tests', () => {
   let element: GrShellCommand;
diff --git a/polygerrit-ui/app/elements/shared/gr-textarea/gr-textarea_test.ts b/polygerrit-ui/app/elements/shared/gr-textarea/gr-textarea_test.ts
index 1e5ae8d..d8a8c44 100644
--- a/polygerrit-ui/app/elements/shared/gr-textarea/gr-textarea_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-textarea/gr-textarea_test.ts
@@ -9,7 +9,7 @@
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {ItemSelectedEvent} from '../gr-autocomplete-dropdown/gr-autocomplete-dropdown';
 import {stubFlags, stubRestApi, waitUntil} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {createAccountWithEmail} from '../../../test/test-data-generators';
 
 suite('gr-textarea tests', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-tooltip-content/gr-tooltip-content_test.ts b/polygerrit-ui/app/elements/shared/gr-tooltip-content/gr-tooltip-content_test.ts
index e190e9b..545e00e 100644
--- a/polygerrit-ui/app/elements/shared/gr-tooltip-content/gr-tooltip-content_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-tooltip-content/gr-tooltip-content_test.ts
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-tooltip-content';
 import {GrTooltipContent} from './gr-tooltip-content';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {GrTooltip} from '../gr-tooltip/gr-tooltip';
 import {query} from '../../../test/test-utils';
 
diff --git a/polygerrit-ui/app/elements/shared/gr-tooltip/gr-tooltip_test.ts b/polygerrit-ui/app/elements/shared/gr-tooltip/gr-tooltip_test.ts
index f2b38da..f0fc102 100644
--- a/polygerrit-ui/app/elements/shared/gr-tooltip/gr-tooltip_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-tooltip/gr-tooltip_test.ts
@@ -7,7 +7,7 @@
 import './gr-tooltip';
 import {GrTooltip} from './gr-tooltip';
 import {queryAndAssert} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-tooltip tests', () => {
   let element: GrTooltip;
diff --git a/polygerrit-ui/app/elements/shared/gr-vote-chip/gr-vote-chip_test.ts b/polygerrit-ui/app/elements/shared/gr-vote-chip/gr-vote-chip_test.ts
index f3906d4..ad1c5b3 100644
--- a/polygerrit-ui/app/elements/shared/gr-vote-chip/gr-vote-chip_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-vote-chip/gr-vote-chip_test.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import '../../../test/common-test-setup-karma';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import {getAppContext} from '../../../services/app-context';
 import './gr-vote-chip';
diff --git a/polygerrit-ui/app/elements/shared/revision-info/revision-info_test.ts b/polygerrit-ui/app/elements/shared/revision-info/revision-info_test.ts
index 33b34d6..ce6687d 100644
--- a/polygerrit-ui/app/elements/shared/revision-info/revision-info_test.ts
+++ b/polygerrit-ui/app/elements/shared/revision-info/revision-info_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import {
   createChange,
diff --git a/polygerrit-ui/app/embed/diff/gr-context-controls/gr-context-controls_test.ts b/polygerrit-ui/app/embed/diff/gr-context-controls/gr-context-controls_test.ts
index 93a5957..4d28f0b 100644
--- a/polygerrit-ui/app/embed/diff/gr-context-controls/gr-context-controls_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-context-controls/gr-context-controls_test.ts
@@ -11,7 +11,7 @@
 import {GrDiffLine, GrDiffLineType} from '../gr-diff/gr-diff-line';
 import {GrDiffGroup, GrDiffGroupType} from '../gr-diff/gr-diff-group';
 import {DiffFileMetaInfo, DiffInfo, SyntaxBlock} from '../../../api/diff';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-context-control tests', () => {
   let element: GrContextControls;
diff --git a/polygerrit-ui/app/embed/diff/gr-coverage-layer/gr-coverage-layer_test.ts b/polygerrit-ui/app/embed/diff/gr-coverage-layer/gr-coverage-layer_test.ts
index 5687b10..cf4a11b 100644
--- a/polygerrit-ui/app/embed/diff/gr-coverage-layer/gr-coverage-layer_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-coverage-layer/gr-coverage-layer_test.ts
@@ -6,6 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import {CoverageRange, CoverageType, Side} from '../../../api/diff';
 import {GrCoverageLayer} from './gr-coverage-layer';
+import {assert} from '@open-wc/testing';
 
 suite('gr-coverage-layer', () => {
   let layer: GrCoverageLayer;
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-builder-element_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-builder-element_test.ts
index f7d9df0..64f89fc 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-builder-element_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-builder-element_test.ts
@@ -29,7 +29,7 @@
 import {createDefaultDiffPrefs} from '../../../constants/constants';
 import {KeyLocations} from '../gr-diff-processor/gr-diff-processor';
 import {BlameInfo} from '../../../types/common';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {EventType} from '../../../types/events';
 
 const DEFAULT_PREFS = createDefaultDiffPrefs();
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-builder-unified_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-builder-unified_test.ts
index 7a9d06d..aa296e7 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-builder-unified_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-builder-unified_test.ts
@@ -14,6 +14,7 @@
 import {createDefaultDiffPrefs} from '../../../constants/constants';
 import {createDiff} from '../../../test/test-data-generators';
 import {queryAndAssert} from '../../../utils/common-util';
+import {assert} from '@open-wc/testing';
 
 suite('GrDiffBuilderUnified tests', () => {
   let prefs: DiffPreferencesInfo;
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-builder/token-highlight-layer_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-builder/token-highlight-layer_test.ts
index a7d5cea..7721595 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-builder/token-highlight-layer_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-builder/token-highlight-layer_test.ts
@@ -12,6 +12,7 @@
 import {html, render} from 'lit';
 import {_testOnly_allTasks} from '../../../utils/async-util';
 import {queryAndAssert} from '../../../test/test-utils';
+import {assert} from '@open-wc/testing';
 
 // MockInteractions.makeMouseEvent always sets buttons to 1.
 function dispatchMouseEvent(
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-cursor/gr-diff-cursor_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-cursor/gr-diff-cursor_test.ts
index 4eb44a1..61fb025 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-cursor/gr-diff-cursor_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-cursor/gr-diff-cursor_test.ts
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import '../gr-diff/gr-diff';
 import './gr-diff-cursor';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {mockPromise, queryAll, queryAndAssert} from '../../../test/test-utils';
 import {createDiff} from '../../../test/test-data-generators';
 import {createDefaultDiffPrefs} from '../../../constants/constants';
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-annotation_test.js b/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-annotation_test.js
index f5aaa53..6ad8968 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-annotation_test.js
+++ b/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-annotation_test.js
@@ -11,7 +11,7 @@
   setSanitizeDOMValue,
 } from '@polymer/polymer/lib/utils/settings.js';
 // eslint-disable-next-line import/named
-import {fixture, html} from '@open-wc/testing';
+import {assert, fixture, html} from '@open-wc/testing';
 
 suite('annotation', () => {
   let str;
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-diff-highlight_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-diff-highlight_test.ts
index d42bbe0..e9ddf95 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-diff-highlight_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-diff-highlight_test.ts
@@ -6,7 +6,7 @@
 import '../../../test/common-test-setup-karma';
 import './gr-diff-highlight';
 import {_getTextOffset} from './gr-range-normalizer';
-import {fixture, fixtureCleanup, html} from '@open-wc/testing';
+import {fixture, fixtureCleanup, html, assert} from '@open-wc/testing';
 import {
   GrDiffHighlight,
   DiffBuilderInterface,
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-image-viewer/util_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-image-viewer/util_test.ts
index 2b8f754..02fa8fc 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-image-viewer/util_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-image-viewer/util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import {FrameConstrainer} from './util';
 
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
index 953a23f..1044eb4 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
@@ -12,7 +12,7 @@
   stubUsers,
   waitUntilObserved,
 } from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {wrapInProvider} from '../../../models/di-provider-element';
 import {
   BrowserModel,
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-processor/gr-diff-processor_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-processor/gr-diff-processor_test.ts
index d99fd6a..34638c2 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-processor/gr-diff-processor_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-processor/gr-diff-processor_test.ts
@@ -9,6 +9,7 @@
 import {GrDiffGroup, GrDiffGroupType} from '../gr-diff/gr-diff-group';
 import {GrDiffProcessor, State} from './gr-diff-processor';
 import {DiffContent} from '../../../types/diff';
+import {assert} from '@open-wc/testing';
 
 suite('gr-diff-processor tests', () => {
   const WHOLE_FILE = -1;
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-selection/gr-diff-selection_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-selection/gr-diff-selection_test.ts
index ebdff48..b8fdc7e 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-selection/gr-diff-selection_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-selection/gr-diff-selection_test.ts
@@ -9,7 +9,7 @@
 import {createDiff} from '../../../test/test-data-generators';
 import {DiffInfo, Side} from '../../../api/diff';
 import {GrFormattedText} from '../../../elements/shared/gr-formatted-text/gr-formatted-text';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 import {mouseDown} from '../../../test/test-utils';
 
 const diffTableTemplate = html`
diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-group_test.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-group_test.ts
index bbf03ae..5fad366 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-group_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-group_test.ts
@@ -10,6 +10,7 @@
   GrDiffGroupType,
   hideInContextControl,
 } from './gr-diff-group';
+import {assert} from '@open-wc/testing';
 
 suite('gr-diff-group tests', () => {
   test('delta line pairs', () => {
diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils_test.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils_test.ts
index a81959d..de5a511 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../../test/common-test-setup-karma';
 import {createElementDiff, formatText, createTabWrapper} from './gr-diff-utils';
 
diff --git a/polygerrit-ui/app/embed/diff/gr-ranged-comment-hint/gr-ranged-comment-hint_test.ts b/polygerrit-ui/app/embed/diff/gr-ranged-comment-hint/gr-ranged-comment-hint_test.ts
index 84c9f57..f0890c3 100644
--- a/polygerrit-ui/app/embed/diff/gr-ranged-comment-hint/gr-ranged-comment-hint_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-ranged-comment-hint/gr-ranged-comment-hint_test.ts
@@ -9,7 +9,7 @@
 import {GrRangedCommentHint} from './gr-ranged-comment-hint';
 import {queryAndAssert} from '../../../test/test-utils';
 import {GrRangeHeader} from '../gr-range-header/gr-range-header';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-ranged-comment-hint tests', () => {
   let element: GrRangedCommentHint;
diff --git a/polygerrit-ui/app/embed/diff/gr-ranged-comment-layer/gr-ranged-comment-layer_test.ts b/polygerrit-ui/app/embed/diff/gr-ranged-comment-layer/gr-ranged-comment-layer_test.ts
index 88203b8..3e808e2 100644
--- a/polygerrit-ui/app/embed/diff/gr-ranged-comment-layer/gr-ranged-comment-layer_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-ranged-comment-layer/gr-ranged-comment-layer_test.ts
@@ -14,6 +14,7 @@
 import {GrDiffLine, GrDiffLineType} from '../gr-diff/gr-diff-line';
 import {Side} from '../../../api/diff';
 import {SinonStub} from 'sinon';
+import {assert} from '@open-wc/testing';
 
 const rangeA: CommentRangeLayer = {
   side: Side.LEFT,
diff --git a/polygerrit-ui/app/embed/diff/gr-selection-action-box/gr-selection-action-box_test.ts b/polygerrit-ui/app/embed/diff/gr-selection-action-box/gr-selection-action-box_test.ts
index f3f54b0..a967df2 100644
--- a/polygerrit-ui/app/embed/diff/gr-selection-action-box/gr-selection-action-box_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-selection-action-box/gr-selection-action-box_test.ts
@@ -7,7 +7,7 @@
 import './gr-selection-action-box';
 import {GrSelectionActionBox} from './gr-selection-action-box';
 import {queryAndAssert} from '../../../test/test-utils';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 suite('gr-selection-action-box', () => {
   let container: HTMLDivElement;
diff --git a/polygerrit-ui/app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker_test.ts b/polygerrit-ui/app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker_test.ts
index ee82d5d..13e10aa 100644
--- a/polygerrit-ui/app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {DiffInfo, GrDiffLineType, Side} from '../../../api/diff';
 import '../../../test/common-test-setup-karma';
 import {mockPromise, stubHighlightService} from '../../../test/test-utils';
diff --git a/polygerrit-ui/app/embed/gr-diff-app-context-init_test.ts b/polygerrit-ui/app/embed/gr-diff-app-context-init_test.ts
index 84fd859..1819730 100644
--- a/polygerrit-ui/app/embed/gr-diff-app-context-init_test.ts
+++ b/polygerrit-ui/app/embed/gr-diff-app-context-init_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {AppContext} from '../services/app-context';
 import '../test/common-test-setup-karma';
 import {createDiffAppContext} from './gr-diff-app-context-init';
diff --git a/polygerrit-ui/app/mixins/hovercard-mixin/hovercard-mixin_test.ts b/polygerrit-ui/app/mixins/hovercard-mixin/hovercard-mixin_test.ts
index c3bf196..239e2a2 100644
--- a/polygerrit-ui/app/mixins/hovercard-mixin/hovercard-mixin_test.ts
+++ b/polygerrit-ui/app/mixins/hovercard-mixin/hovercard-mixin_test.ts
@@ -9,7 +9,7 @@
 import {customElement} from 'lit/decorators.js';
 import {MockPromise, mockPromise, pressKey} from '../../test/test-utils';
 import {findActiveElement, Key} from '../../utils/dom-util';
-import {fixture, html} from '@open-wc/testing';
+import {fixture, html, assert} from '@open-wc/testing';
 
 const base = HovercardMixin(LitElement);
 
diff --git a/polygerrit-ui/app/models/accounts-model/accounts-model_test.ts b/polygerrit-ui/app/models/accounts-model/accounts-model_test.ts
index 8071297..b869191 100644
--- a/polygerrit-ui/app/models/accounts-model/accounts-model_test.ts
+++ b/polygerrit-ui/app/models/accounts-model/accounts-model_test.ts
@@ -9,6 +9,7 @@
 import {getAppContext} from '../../services/app-context';
 import {stubRestApi} from '../../test/test-utils';
 import {AccountsModel} from './accounts-model';
+import {assert} from '@open-wc/testing';
 
 suite('accounts-model tests', () => {
   let model: AccountsModel;
diff --git a/polygerrit-ui/app/models/bulk-actions/bulk-actions-model_test.ts b/polygerrit-ui/app/models/bulk-actions/bulk-actions-model_test.ts
index 4a991da..b1bfa26 100644
--- a/polygerrit-ui/app/models/bulk-actions/bulk-actions-model_test.ts
+++ b/polygerrit-ui/app/models/bulk-actions/bulk-actions-model_test.ts
@@ -29,6 +29,7 @@
 import {SinonStubbedMember} from 'sinon';
 import {RestApiService} from '../../services/gr-rest-api/gr-rest-api';
 import {ReviewInput} from '../../types/common';
+import {assert} from '@open-wc/testing';
 
 suite('bulk actions model test', () => {
   let bulkActionsModel: BulkActionsModel;
diff --git a/polygerrit-ui/app/models/change/change-model_test.ts b/polygerrit-ui/app/models/change/change-model_test.ts
index 6773f78..4b03eb5 100644
--- a/polygerrit-ui/app/models/change/change-model_test.ts
+++ b/polygerrit-ui/app/models/change/change-model_test.ts
@@ -30,6 +30,7 @@
 import {GerritView} from '../../services/router/router-model';
 import {ChangeState, LoadingStatus, updateChangeWithEdit} from './change-model';
 import {ChangeModel} from './change-model';
+import {assert} from '@open-wc/testing';
 
 suite('updateChangeWithEdit() tests', () => {
   test('undefined change', async () => {
diff --git a/polygerrit-ui/app/models/checks/checks-model_test.ts b/polygerrit-ui/app/models/checks/checks-model_test.ts
index c3fe7ff..9cac48b 100644
--- a/polygerrit-ui/app/models/checks/checks-model_test.ts
+++ b/polygerrit-ui/app/models/checks/checks-model_test.ts
@@ -19,6 +19,7 @@
 import {waitUntil, waitUntilCalled} from '../../test/test-utils';
 import {ParsedChangeInfo} from '../../types/types';
 import {changeModelToken} from '../change/change-model';
+import {assert} from '@open-wc/testing';
 
 const PLUGIN_NAME = 'test-plugin';
 
diff --git a/polygerrit-ui/app/models/comments/comments-model_test.ts b/polygerrit-ui/app/models/comments/comments-model_test.ts
index ddfc6d7..fcd3b49 100644
--- a/polygerrit-ui/app/models/comments/comments-model_test.ts
+++ b/polygerrit-ui/app/models/comments/comments-model_test.ts
@@ -21,6 +21,7 @@
 import {GerritView} from '../../services/router/router-model';
 import {PathToCommentsInfoMap} from '../../types/common';
 import {changeModelToken} from '../change/change-model';
+import {assert} from '@open-wc/testing';
 
 suite('comments model tests', () => {
   test('updateStateDeleteDraft', () => {
diff --git a/polygerrit-ui/app/models/dependency_test.ts b/polygerrit-ui/app/models/dependency_test.ts
index 487b0dc..fc6b13d 100644
--- a/polygerrit-ui/app/models/dependency_test.ts
+++ b/polygerrit-ui/app/models/dependency_test.ts
@@ -7,7 +7,7 @@
 import {html, LitElement} from 'lit';
 import {customElement, property, query} from 'lit/decorators.js';
 import '../test/common-test-setup-karma.js';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 
 interface FooService {
   value: string;
diff --git a/polygerrit-ui/app/models/di-provider-element_test.ts b/polygerrit-ui/app/models/di-provider-element_test.ts
index 6134307..501e45c 100644
--- a/polygerrit-ui/app/models/di-provider-element_test.ts
+++ b/polygerrit-ui/app/models/di-provider-element_test.ts
@@ -7,7 +7,7 @@
 import {customElement, state} from 'lit/decorators.js';
 import {define, resolve} from './dependency';
 import '../test/common-test-setup-karma.js';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {DIProviderElement, wrapInProvider} from './di-provider-element';
 import {BehaviorSubject} from 'rxjs';
 import {waitUntilObserved} from '../test/test-utils';
diff --git a/polygerrit-ui/app/models/plugins/plugins-model_test.ts b/polygerrit-ui/app/models/plugins/plugins-model_test.ts
index 8f75865..1c97ec6 100644
--- a/polygerrit-ui/app/models/plugins/plugins-model_test.ts
+++ b/polygerrit-ui/app/models/plugins/plugins-model_test.ts
@@ -8,6 +8,7 @@
 import {ChecksApiConfig, ChecksProvider, ResponseCode} from '../../api/checks';
 import {ChecksPlugin, ChecksUpdate, PluginsModel} from './plugins-model';
 import {createRunResult} from '../../test/test-data-generators';
+import {assert} from '@open-wc/testing';
 
 const PLUGIN_NAME = 'test-plugin';
 
diff --git a/polygerrit-ui/app/scripts/gr-reviewer-suggestions-provider/gr-reviewer-suggestions-provider_test.ts b/polygerrit-ui/app/scripts/gr-reviewer-suggestions-provider/gr-reviewer-suggestions-provider_test.ts
index df3be36..3618585 100644
--- a/polygerrit-ui/app/scripts/gr-reviewer-suggestions-provider/gr-reviewer-suggestions-provider_test.ts
+++ b/polygerrit-ui/app/scripts/gr-reviewer-suggestions-provider/gr-reviewer-suggestions-provider_test.ts
@@ -21,6 +21,7 @@
   createChange,
   createServerInfo,
 } from '../../test/test-data-generators';
+import {assert} from '@open-wc/testing';
 
 const accounts: AccountDetailInfo[] = [
   createAccountDetailWithIdNameAndEmail(1),
diff --git a/polygerrit-ui/app/services/app-context-init_test.ts b/polygerrit-ui/app/services/app-context-init_test.ts
index 4527a6a..24b559a 100644
--- a/polygerrit-ui/app/services/app-context-init_test.ts
+++ b/polygerrit-ui/app/services/app-context-init_test.ts
@@ -7,6 +7,7 @@
 import {AppContext} from './app-context.js';
 import {Finalizable} from './registry';
 import {createTestAppContext} from '../test/test-app-context-init.js';
+import {assert} from '@open-wc/testing';
 
 suite('app context initializer tests', () => {
   let appContext: AppContext & Finalizable;
diff --git a/polygerrit-ui/app/services/flags/flags_test.ts b/polygerrit-ui/app/services/flags/flags_test.ts
index 8d6287c..4c94151 100644
--- a/polygerrit-ui/app/services/flags/flags_test.ts
+++ b/polygerrit-ui/app/services/flags/flags_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../test/common-test-setup-karma';
 import {FlagsServiceImplementation} from './flags_impl';
 
diff --git a/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts b/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts
index 18b898e..ed46150 100644
--- a/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts
+++ b/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts
@@ -10,6 +10,7 @@
 import {EventEmitterService} from '../gr-event-interface/gr-event-interface';
 import {SinonFakeTimers} from 'sinon';
 import {AuthRequestInit, DefaultAuthOptions} from './gr-auth';
+import {assert} from '@open-wc/testing';
 
 suite('gr-auth', () => {
   let auth: Auth;
diff --git a/polygerrit-ui/app/services/gr-event-interface/gr-event-interface_test.js b/polygerrit-ui/app/services/gr-event-interface/gr-event-interface_test.js
index caa80f6..2202f01 100644
--- a/polygerrit-ui/app/services/gr-event-interface/gr-event-interface_test.js
+++ b/polygerrit-ui/app/services/gr-event-interface/gr-event-interface_test.js
@@ -6,6 +6,7 @@
 import '../../test/common-test-setup-karma.js';
 import {mockPromise} from '../../test/test-utils.js';
 import {EventEmitter} from './gr-event-interface_impl.js';
+import {assert} from '@open-wc/testing';
 
 suite('gr-event-interface tests', () => {
   let gerrit;
diff --git a/polygerrit-ui/app/services/gr-reporting/gr-reporting_mock_test.ts b/polygerrit-ui/app/services/gr-reporting/gr-reporting_mock_test.ts
index 561387c..90616be 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting_mock_test.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting_mock_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../test/common-test-setup-karma';
 import {GrReporting} from './gr-reporting_impl';
 import {grReportingMock} from './gr-reporting_mock';
diff --git a/polygerrit-ui/app/services/gr-reporting/gr-reporting_test.ts b/polygerrit-ui/app/services/gr-reporting/gr-reporting_test.ts
index dba51d2..dd19c9d 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting_test.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting_test.ts
@@ -12,6 +12,7 @@
 import {getAppContext} from '../app-context';
 import {Deduping} from '../../api/reporting';
 import {SinonFakeTimers} from 'sinon';
+import {assert} from '@open-wc/testing';
 
 suite('gr-reporting tests', () => {
   // We have to type as any because we access
diff --git a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.js b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.js
index 864d7cd..a0f74c7 100644
--- a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.js
+++ b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.js
@@ -22,6 +22,7 @@
 import {GrRestApiServiceImpl} from './gr-rest-api-impl.js';
 import {CommentSide} from '../../constants/constants.js';
 import {EDIT, PARENT} from '../../types/common.js';
+import {assert} from '@open-wc/testing';
 
 const EXPECTED_QUERY_OPTIONS = listChangesOptionsToHex(
     ListChangesOption.CHANGE_ACTIONS,
diff --git a/polygerrit-ui/app/services/highlight/highlight-service_test.ts b/polygerrit-ui/app/services/highlight/highlight-service_test.ts
index 4c38a68..3508797 100644
--- a/polygerrit-ui/app/services/highlight/highlight-service_test.ts
+++ b/polygerrit-ui/app/services/highlight/highlight-service_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../test/common-test-setup-karma';
 import {waitUntil} from '../../test/test-utils';
 import {grReportingMock} from '../gr-reporting/gr-reporting_mock';
diff --git a/polygerrit-ui/app/services/registry_test.ts b/polygerrit-ui/app/services/registry_test.ts
index d2510ff..290855d 100644
--- a/polygerrit-ui/app/services/registry_test.ts
+++ b/polygerrit-ui/app/services/registry_test.ts
@@ -5,6 +5,7 @@
  */
 import {create, Finalizable, Registry} from './registry';
 import '../test/common-test-setup-karma.js';
+import {assert} from '@open-wc/testing';
 
 class Foo implements Finalizable {
   constructor(private readonly final: string[]) {}
diff --git a/polygerrit-ui/app/services/scheduler/fake-scheduler_test.ts b/polygerrit-ui/app/services/scheduler/fake-scheduler_test.ts
index feb93cf..166f18f 100644
--- a/polygerrit-ui/app/services/scheduler/fake-scheduler_test.ts
+++ b/polygerrit-ui/app/services/scheduler/fake-scheduler_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../test/common-test-setup-karma.js';
 import {assertFails} from '../../test/test-utils.js';
 import {FakeScheduler} from './fake-scheduler';
diff --git a/polygerrit-ui/app/services/scheduler/max-in-flight-scheduler_test.ts b/polygerrit-ui/app/services/scheduler/max-in-flight-scheduler_test.ts
index 9e76821..53d92ca 100644
--- a/polygerrit-ui/app/services/scheduler/max-in-flight-scheduler_test.ts
+++ b/polygerrit-ui/app/services/scheduler/max-in-flight-scheduler_test.ts
@@ -8,6 +8,7 @@
 import {Scheduler} from './scheduler';
 import {MaxInFlightScheduler} from './max-in-flight-scheduler';
 import {FakeScheduler} from './fake-scheduler';
+import {assert} from '@open-wc/testing';
 
 suite('max-in-flight scheduler', () => {
   let fakeScheduler: FakeScheduler<number>;
diff --git a/polygerrit-ui/app/services/scheduler/retry-scheduler_test.ts b/polygerrit-ui/app/services/scheduler/retry-scheduler_test.ts
index 988b167..d1877b6 100644
--- a/polygerrit-ui/app/services/scheduler/retry-scheduler_test.ts
+++ b/polygerrit-ui/app/services/scheduler/retry-scheduler_test.ts
@@ -9,6 +9,7 @@
 import {RetryScheduler, RetryError} from './retry-scheduler';
 import {FakeScheduler} from './fake-scheduler';
 import {SinonFakeTimers} from 'sinon';
+import {assert} from '@open-wc/testing';
 
 suite('retry scheduler', () => {
   let clock: SinonFakeTimers;
diff --git a/polygerrit-ui/app/services/scheduler/scheduler_test.ts b/polygerrit-ui/app/services/scheduler/scheduler_test.ts
index 186627a..2ab75c1 100644
--- a/polygerrit-ui/app/services/scheduler/scheduler_test.ts
+++ b/polygerrit-ui/app/services/scheduler/scheduler_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../test/common-test-setup-karma.js';
 import {assertFails} from '../../test/test-utils.js';
 import {BaseScheduler} from './scheduler';
diff --git a/polygerrit-ui/app/services/service-worker-installer_test.ts b/polygerrit-ui/app/services/service-worker-installer_test.ts
index d6b0c02..ea60803 100644
--- a/polygerrit-ui/app/services/service-worker-installer_test.ts
+++ b/polygerrit-ui/app/services/service-worker-installer_test.ts
@@ -6,6 +6,7 @@
 import {getAppContext} from './app-context';
 import '../test/common-test-setup-karma';
 import {ServiceWorkerInstaller} from './service-worker-installer';
+import {assert} from '@open-wc/testing';
 
 suite('service woerker installler tests', () => {
   let serviceWorkerInstaller: ServiceWorkerInstaller;
diff --git a/polygerrit-ui/app/services/shortcuts/shortcuts-service_test.ts b/polygerrit-ui/app/services/shortcuts/shortcuts-service_test.ts
index 9f0a34f..e59f986 100644
--- a/polygerrit-ui/app/services/shortcuts/shortcuts-service_test.ts
+++ b/polygerrit-ui/app/services/shortcuts/shortcuts-service_test.ts
@@ -14,6 +14,7 @@
 import {Binding, Key, Modifier} from '../../utils/dom-util';
 import {getAppContext} from '../app-context';
 import {pressKey} from '../../test/test-utils';
+import {assert} from '@open-wc/testing';
 
 const KEY_A: Binding = {key: 'a'};
 
diff --git a/polygerrit-ui/app/services/storage/gr-storage_test.ts b/polygerrit-ui/app/services/storage/gr-storage_test.ts
index aca8d35..c488e87 100644
--- a/polygerrit-ui/app/services/storage/gr-storage_test.ts
+++ b/polygerrit-ui/app/services/storage/gr-storage_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../../test/common-test-setup-karma';
 import {PatchSetNum} from '../../types/common';
 import {StorageLocation} from './gr-storage';
diff --git a/polygerrit-ui/app/test/common-test-setup.ts b/polygerrit-ui/app/test/common-test-setup.ts
index 181fadf..7484bda 100644
--- a/polygerrit-ui/app/test/common-test-setup.ts
+++ b/polygerrit-ui/app/test/common-test-setup.ts
@@ -28,9 +28,7 @@
 } from './test-utils';
 import {safeTypesBridge} from '../utils/safe-types-util';
 import {initGlobalVariables} from '../elements/gr-app-global-var-init';
-import 'chai/chai';
-import {chaiDomDiff} from '@open-wc/semantic-dom-diff';
-import {fixtureCleanup} from '@open-wc/testing';
+import {assert, fixtureCleanup} from '@open-wc/testing';
 import {
   _testOnly_defaultResinReportHandler,
   installPolymerResin,
@@ -46,15 +44,10 @@
 
 declare global {
   interface Window {
-    assert: typeof chai.assert;
     sinon: typeof sinon;
-    chai: typeof chai;
   }
-  let assert: typeof chai.assert;
   let sinon: typeof sinon;
 }
-window.assert = chai.assert;
-window.chai.use(chaiDomDiff);
 
 window.sinon = sinon;
 
diff --git a/polygerrit-ui/app/test/test-utils.ts b/polygerrit-ui/app/test/test-utils.ts
index 2cd3f509..47c21cc 100644
--- a/polygerrit-ui/app/test/test-utils.ts
+++ b/polygerrit-ui/app/test/test-utils.ts
@@ -19,6 +19,7 @@
 import {Observable} from 'rxjs';
 import {filter, take, timeout} from 'rxjs/operators';
 import {HighlightService} from '../services/highlight/highlight-service';
+import {assert} from '@open-wc/testing';
 export {query, queryAll, queryAndAssert} from '../utils/common-util';
 
 export interface MockPromise<T> extends Promise<T> {
diff --git a/polygerrit-ui/app/utils/access-util_test.ts b/polygerrit-ui/app/utils/access-util_test.ts
index 871ab85..fdde33e 100644
--- a/polygerrit-ui/app/utils/access-util_test.ts
+++ b/polygerrit-ui/app/utils/access-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../test/common-test-setup-karma';
 import {toSortedPermissionsArray} from './access-util';
 
diff --git a/polygerrit-ui/app/utils/account-util_test.ts b/polygerrit-ui/app/utils/account-util_test.ts
index e181d6d..83aa2d1 100644
--- a/polygerrit-ui/app/utils/account-util_test.ts
+++ b/polygerrit-ui/app/utils/account-util_test.ts
@@ -33,6 +33,7 @@
   createGroupInfo,
   createServerInfo,
 } from '../test/test-data-generators';
+import {assert} from '@open-wc/testing';
 
 const EMPTY = {};
 const ERNIE = {name: 'Ernie'};
diff --git a/polygerrit-ui/app/utils/admin-nav-util_test.ts b/polygerrit-ui/app/utils/admin-nav-util_test.ts
index 844ff95..01f8481 100644
--- a/polygerrit-ui/app/utils/admin-nav-util_test.ts
+++ b/polygerrit-ui/app/utils/admin-nav-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {AccountDetailInfo, GroupId, RepoName, Timestamp} from '../api/rest-api';
 import '../test/common-test-setup-karma';
 import {AdminNavLinksOption, getAdminLinks} from './admin-nav-util';
diff --git a/polygerrit-ui/app/utils/async-util_test.ts b/polygerrit-ui/app/utils/async-util_test.ts
index 252bfe6..aa4b5fc 100644
--- a/polygerrit-ui/app/utils/async-util_test.ts
+++ b/polygerrit-ui/app/utils/async-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {SinonFakeTimers} from 'sinon';
 import '../test/common-test-setup-karma';
 import {asyncForeach, debounceP} from './async-util';
diff --git a/polygerrit-ui/app/utils/attention-set-util_test.ts b/polygerrit-ui/app/utils/attention-set-util_test.ts
index 85d6c09..2b302c7 100644
--- a/polygerrit-ui/app/utils/attention-set-util_test.ts
+++ b/polygerrit-ui/app/utils/attention-set-util_test.ts
@@ -15,6 +15,7 @@
 import {getReason, hasAttention} from './attention-set-util';
 import {DefaultDisplayNameConfig} from '../api/rest-api';
 import {AccountsVisibility} from '../constants/constants';
+import {assert} from '@open-wc/testing';
 
 const KERMIT: AccountInfo = {
   email: 'kermit@gmail.com' as EmailAddress,
diff --git a/polygerrit-ui/app/utils/change-util_test.ts b/polygerrit-ui/app/utils/change-util_test.ts
index 9f6f23f..b1b37a5 100644
--- a/polygerrit-ui/app/utils/change-util_test.ts
+++ b/polygerrit-ui/app/utils/change-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {ChangeStatus} from '../constants/constants';
 import {ChangeStates} from '../elements/shared/gr-change-status/gr-change-status';
 import '../test/common-test-setup-karma';
diff --git a/polygerrit-ui/app/utils/comment-util_test.ts b/polygerrit-ui/app/utils/comment-util_test.ts
index 4310396..a22ded1 100644
--- a/polygerrit-ui/app/utils/comment-util_test.ts
+++ b/polygerrit-ui/app/utils/comment-util_test.ts
@@ -29,6 +29,7 @@
   Timestamp,
   UrlEncodedCommentId,
 } from '../types/common';
+import {assert} from '@open-wc/testing';
 
 suite('comment-util', () => {
   test('isUnresolved', () => {
diff --git a/polygerrit-ui/app/utils/common-util_test.ts b/polygerrit-ui/app/utils/common-util_test.ts
index c9ba060..33080ca 100644
--- a/polygerrit-ui/app/utils/common-util_test.ts
+++ b/polygerrit-ui/app/utils/common-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../test/common-test-setup-karma';
 import {
   hasOwnProperty,
diff --git a/polygerrit-ui/app/utils/date-util_test.ts b/polygerrit-ui/app/utils/date-util_test.ts
index 7eb9905..85fcd70 100644
--- a/polygerrit-ui/app/utils/date-util_test.ts
+++ b/polygerrit-ui/app/utils/date-util_test.ts
@@ -14,6 +14,7 @@
   formatDate,
   wasYesterday,
 } from './date-util';
+import {assert} from '@open-wc/testing';
 
 suite('date-util tests', () => {
   suite('parseDate', () => {
diff --git a/polygerrit-ui/app/utils/deep-util_test.ts b/polygerrit-ui/app/utils/deep-util_test.ts
index fbbd7e7c..2b5ec65 100644
--- a/polygerrit-ui/app/utils/deep-util_test.ts
+++ b/polygerrit-ui/app/utils/deep-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../test/common-test-setup-karma';
 import {deepEqual} from './deep-util';
 
diff --git a/polygerrit-ui/app/utils/display-name-util_test.ts b/polygerrit-ui/app/utils/display-name-util_test.ts
index 9510771..c820b92 100644
--- a/polygerrit-ui/app/utils/display-name-util_test.ts
+++ b/polygerrit-ui/app/utils/display-name-util_test.ts
@@ -23,6 +23,7 @@
   createGroupInfo,
   createServerInfo,
 } from '../test/test-data-generators';
+import {assert} from '@open-wc/testing';
 
 suite('display-name-utils tests', () => {
   const config: ServerInfo = {
diff --git a/polygerrit-ui/app/utils/dom-util_test.ts b/polygerrit-ui/app/utils/dom-util_test.ts
index 3732718..b678167 100644
--- a/polygerrit-ui/app/utils/dom-util_test.ts
+++ b/polygerrit-ui/app/utils/dom-util_test.ts
@@ -16,7 +16,7 @@
 } from './dom-util';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {mockPromise, queryAndAssert} from '../test/test-utils';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 import {LitElement, html} from 'lit';
 import {customElement} from 'lit/decorators.js';
 
diff --git a/polygerrit-ui/app/utils/focusable_test.ts b/polygerrit-ui/app/utils/focusable_test.ts
index 8b697da..d428ca72 100644
--- a/polygerrit-ui/app/utils/focusable_test.ts
+++ b/polygerrit-ui/app/utils/focusable_test.ts
@@ -6,7 +6,7 @@
 import '../test/common-test-setup-karma';
 import {getFocusableElements, getFocusableElementsReverse} from './focusable';
 import {html, render} from 'lit';
-import {fixture} from '@open-wc/testing';
+import {fixture, assert} from '@open-wc/testing';
 
 async function createDom() {
   const container = await fixture<HTMLDivElement>(html`<div></div>`);
diff --git a/polygerrit-ui/app/utils/label-util_test.ts b/polygerrit-ui/app/utils/label-util_test.ts
index faf7e00..f47ba91 100644
--- a/polygerrit-ui/app/utils/label-util_test.ts
+++ b/polygerrit-ui/app/utils/label-util_test.ts
@@ -47,6 +47,7 @@
   LabelNameToInfoMap,
   SubmitRequirementExpressionInfoStatus,
 } from '../api/rest-api';
+import {assert} from '@open-wc/testing';
 
 const VALUES_0 = {
   '0': 'neutral',
diff --git a/polygerrit-ui/app/utils/lit-util_test.ts b/polygerrit-ui/app/utils/lit-util_test.ts
index a20e919..ef653e7 100644
--- a/polygerrit-ui/app/utils/lit-util_test.ts
+++ b/polygerrit-ui/app/utils/lit-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../test/common-test-setup-karma';
 import {HtmlPatched} from './lit-util';
 
diff --git a/polygerrit-ui/app/utils/patch-set-util_test.ts b/polygerrit-ui/app/utils/patch-set-util_test.ts
index e4adf8f..6548963 100644
--- a/polygerrit-ui/app/utils/patch-set-util_test.ts
+++ b/polygerrit-ui/app/utils/patch-set-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../test/common-test-setup-karma';
 import {
   createChange,
diff --git a/polygerrit-ui/app/utils/path-list-util_test.ts b/polygerrit-ui/app/utils/path-list-util_test.ts
index 851883c..41c0e8d 100644
--- a/polygerrit-ui/app/utils/path-list-util_test.ts
+++ b/polygerrit-ui/app/utils/path-list-util_test.ts
@@ -14,6 +14,7 @@
 } from './path-list-util';
 import {FileInfo} from '../api/rest-api';
 import {hasOwnProperty} from './common-util';
+import {assert} from '@open-wc/testing';
 
 suite('path-list-utl tests', () => {
   test('special sort', () => {
diff --git a/polygerrit-ui/app/utils/router-util_test.ts b/polygerrit-ui/app/utils/router-util_test.ts
index 7ca44d5..2c74343 100644
--- a/polygerrit-ui/app/utils/router-util_test.ts
+++ b/polygerrit-ui/app/utils/router-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {
   RepoName,
   BranchName,
diff --git a/polygerrit-ui/app/utils/safe-types-util_test.ts b/polygerrit-ui/app/utils/safe-types-util_test.ts
index 6d223da..90a0cc9 100644
--- a/polygerrit-ui/app/utils/safe-types-util_test.ts
+++ b/polygerrit-ui/app/utils/safe-types-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../test/common-test-setup-karma';
 import {safeTypesBridge, _testOnly_SafeUrl} from './safe-types-util';
 
diff --git a/polygerrit-ui/app/utils/service-worker-util_test.ts b/polygerrit-ui/app/utils/service-worker-util_test.ts
index 0caea3b..019a966 100644
--- a/polygerrit-ui/app/utils/service-worker-util_test.ts
+++ b/polygerrit-ui/app/utils/service-worker-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {Timestamp} from '../api/rest-api';
 import '../test/common-test-setup-karma';
 import {
diff --git a/polygerrit-ui/app/utils/string-util_test.ts b/polygerrit-ui/app/utils/string-util_test.ts
index efc64cf..4d62a59 100644
--- a/polygerrit-ui/app/utils/string-util_test.ts
+++ b/polygerrit-ui/app/utils/string-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../test/common-test-setup-karma';
 import {
   pluralize,
diff --git a/polygerrit-ui/app/utils/submit-requirement-util_test.ts b/polygerrit-ui/app/utils/submit-requirement-util_test.ts
index 35121e8..68cc7a9 100644
--- a/polygerrit-ui/app/utils/submit-requirement-util_test.ts
+++ b/polygerrit-ui/app/utils/submit-requirement-util_test.ts
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import {assert} from '@open-wc/testing';
 import {SubmitRequirementExpressionInfo} from '../api/rest-api';
 import '../test/common-test-setup-karma';
 import {
diff --git a/polygerrit-ui/app/utils/syntax-util_test.ts b/polygerrit-ui/app/utils/syntax-util_test.ts
index 4d381fb..ffd9d5c 100644
--- a/polygerrit-ui/app/utils/syntax-util_test.ts
+++ b/polygerrit-ui/app/utils/syntax-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import '../test/common-test-setup-karma';
 import './syntax-util';
 import {
diff --git a/polygerrit-ui/app/utils/url-util_test.ts b/polygerrit-ui/app/utils/url-util_test.ts
index b2a1232..b12fc8f 100644
--- a/polygerrit-ui/app/utils/url-util_test.ts
+++ b/polygerrit-ui/app/utils/url-util_test.ts
@@ -18,6 +18,7 @@
 } from './url-util';
 import {getAppContext, AppContext} from '../services/app-context';
 import {stubRestApi} from '../test/test-utils';
+import {assert} from '@open-wc/testing';
 
 suite('url-util tests', () => {
   let appContext: AppContext;
diff --git a/polygerrit-ui/app/workers/service-worker-class_test.ts b/polygerrit-ui/app/workers/service-worker-class_test.ts
index 2bff51c..6c46b12 100644
--- a/polygerrit-ui/app/workers/service-worker-class_test.ts
+++ b/polygerrit-ui/app/workers/service-worker-class_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import {assert} from '@open-wc/testing';
 import {Timestamp} from '../api/rest-api';
 import '../test/common-test-setup-karma';
 import {
diff --git a/polygerrit-ui/package.json b/polygerrit-ui/package.json
index 60385d1..9a87b3d 100644
--- a/polygerrit-ui/package.json
+++ b/polygerrit-ui/package.json
@@ -3,7 +3,6 @@
   "description": "Gerrit Code Review - Polygerrit dev dependencies",
   "browser": true,
   "dependencies": {
-    "@types/chai": "^4.3.1",
     "@types/mocha": "^9.1.1",
     "@types/sinon": "^10.0.0"
   },
@@ -14,7 +13,6 @@
     "@polymer/iron-test-helpers": "^3.0.1",
     "@polymer/test-fixture": "^4.0.2",
     "accessibility-developer-tools": "^2.12.0",
-    "chai": "^4.3.6",
     "karma": "^6.3.20",
     "karma-chrome-launcher": "^3.1.1",
     "karma-mocha": "^2.0.1",
diff --git a/polygerrit-ui/yarn.lock b/polygerrit-ui/yarn.lock
index a8505e0..8bffeb2 100644
--- a/polygerrit-ui/yarn.lock
+++ b/polygerrit-ui/yarn.lock
@@ -1797,11 +1797,6 @@
   resolved "https://registry.yarnpkg.com/assert-plus/-/assert-plus-1.0.0.tgz#f12e0f3c5d77b0b1cdd9146942e4e96c1e4dd525"
   integrity sha1-8S4PPF13sLHN2RRpQuTpbB5N1SU=
 
-assertion-error@^1.1.0:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.1.0.tgz#e60b6b0e8f301bd97e5375215bda406c85118c0b"
-  integrity sha512-jgsaNduz+ndvGyFt3uSuWqvy4lCnIJiovtouQN5JZHOKCS2QuhEdbcQHFhVksz2N2U9hXJo8odG7ETyWlEeuDw==
-
 astral-regex@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/astral-regex/-/astral-regex-2.0.0.tgz#483143c567aeed4785759c0865786dc77d7d2e31"
@@ -2029,19 +2024,6 @@
   dependencies:
     axe-core "^4.3.3"
 
-chai@^4.3.6:
-  version "4.3.6"
-  resolved "https://registry.yarnpkg.com/chai/-/chai-4.3.6.tgz#ffe4ba2d9fa9d6680cc0b370adae709ec9011e9c"
-  integrity sha512-bbcp3YfHCUzMOvKqsztczerVgBKSsEijCySNlHHbX3VG1nskvqjz5Rfso1gGwD6w6oOV3eI60pKuMOV5MV7p3Q==
-  dependencies:
-    assertion-error "^1.1.0"
-    check-error "^1.0.2"
-    deep-eql "^3.0.1"
-    get-func-name "^2.0.0"
-    loupe "^2.3.1"
-    pathval "^1.1.1"
-    type-detect "^4.0.5"
-
 chalk@^2.0.0, chalk@^2.0.1, chalk@^2.1.0, chalk@^2.4.2:
   version "2.4.2"
   resolved "https://registry.yarnpkg.com/chalk/-/chalk-2.4.2.tgz#cd42541677a54333cf541a49108c1432b44c9424"
@@ -2059,11 +2041,6 @@
     ansi-styles "^4.1.0"
     supports-color "^7.1.0"
 
-check-error@^1.0.2:
-  version "1.0.2"
-  resolved "https://registry.yarnpkg.com/check-error/-/check-error-1.0.2.tgz#574d312edd88bb5dd8912e9286dd6c0aed4aac82"
-  integrity sha1-V00xLt2Iu13YkS6Sht1sCu1KrII=
-
 chokidar@3.5.3:
   version "3.5.3"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-3.5.3.tgz#1cf37c8707b932bd1af1ae22c0432e2acd1903bd"
@@ -2357,13 +2334,6 @@
   resolved "https://registry.yarnpkg.com/decamelize/-/decamelize-4.0.0.tgz#aa472d7bf660eb15f3494efd531cab7f2a709837"
   integrity sha512-9iE1PgSik9HeIIw2JO94IidnE3eBoQrFJ3w7sFuzSX4DpmZ3v5sZpUiV5Swcf6mQEF+Y0ru8Neo+p+nyh2J+hQ==
 
-deep-eql@^3.0.1:
-  version "3.0.1"
-  resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-3.0.1.tgz#dfc9404400ad1c8fe023e7da1df1c147c4b444df"
-  integrity sha512-+QeIQyN5ZuO+3Uk5DYh6/1eKO0m0YmJFGNmFHGACpf1ClL1nmlV/p4gNgbl2pJGxgXb4faqo6UE+M5ACEMyVcw==
-  dependencies:
-    type-detect "^4.0.0"
-
 deep-equal@~1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/deep-equal/-/deep-equal-1.0.1.tgz#f5d260292b660e084eff4cdbc9f08ad3247448b5"
@@ -2823,11 +2793,6 @@
   resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-2.0.5.tgz#4f94412a82db32f36e3b0b9741f8a97feb031f7e"
   integrity sha512-DyFP3BM/3YHTQOCUL/w0OZHR0lpKeGrxotcHWcqNEdnltqFwXVfhEBQ94eIo34AfQpo0rGki4cyIiftY06h2Fg==
 
-get-func-name@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/get-func-name/-/get-func-name-2.0.0.tgz#ead774abee72e20409433a066366023dd6887a41"
-  integrity sha1-6td0q+5y4gQJQzoGY2YCPdaIekE=
-
 get-intrinsic@^1.0.2:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/get-intrinsic/-/get-intrinsic-1.1.1.tgz#15f59f376f855c446963948f0d24cd3637b4abc6"
@@ -3634,13 +3599,6 @@
     rfdc "^1.3.0"
     streamroller "^3.1.1"
 
-loupe@^2.3.1:
-  version "2.3.4"
-  resolved "https://registry.yarnpkg.com/loupe/-/loupe-2.3.4.tgz#7e0b9bffc76f148f9be769cb1321d3dcf3cb25f3"
-  integrity sha512-OvKfgCC2Ndby6aSTREl5aCCPTNIzlDfQZvZxNUrBrihDhL3xcrYegTblhmEiCrg2kKQz4XsFIaemE5BF4ybSaQ==
-  dependencies:
-    get-func-name "^2.0.0"
-
 lower-case@^2.0.2:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/lower-case/-/lower-case-2.0.2.tgz#6fa237c63dbdc4a82ca0fd882e4722dc5e634e28"
@@ -4060,11 +4018,6 @@
   resolved "https://registry.yarnpkg.com/path-type/-/path-type-4.0.0.tgz#84ed01c0a7ba380afe09d90a8c180dcd9d03043b"
   integrity sha512-gDKb8aZMDeD/tZWs9P6+q0J9Mwkdl6xMV8TjnGP3qJVJ06bdMgkbBlLU8IdfOsIsFz2BW1rNVT3XuNEl8zPAvw==
 
-pathval@^1.1.1:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/pathval/-/pathval-1.1.1.tgz#8534e77a77ce7ac5a2512ea21e0fdb8fcf6c3d8d"
-  integrity sha512-Dp6zGqpTdETdR63lehJYPeIOqpiNBNtc7BpWSLrOje7UaIsE5aY92r/AunQA7rsXvet3lrJ3JnZX29UPTKXyKQ==
-
 performance-now@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/performance-now/-/performance-now-2.1.0.tgz#6309f4e0e5fa913ec1c69307ae364b4b377c9e7b"
@@ -4765,7 +4718,7 @@
   resolved "https://registry.yarnpkg.com/tweetnacl/-/tweetnacl-0.14.5.tgz#5ae68177f192d4456269d108afa93ff8743f4f64"
   integrity sha1-WuaBd/GS1EViadEIr6k/+HQ/T2Q=
 
-type-detect@4.0.8, type-detect@^4.0.0, type-detect@^4.0.5, type-detect@^4.0.8:
+type-detect@4.0.8, type-detect@^4.0.8:
   version "4.0.8"
   resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.8.tgz#7646fb5f18871cfbb7749e69bd39a6388eb7450c"
   integrity sha512-0fr/mIH1dlO+x7TlcMy+bIDqKPsw/70tVyeHW787goQjhmqaZe10uwLujubK9q9Lg6Fiho1KUKDYz0Z7k7g5/g==