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 2c397e0..60bcf8a 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-access-section';
 import {
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 fe5aa22..750beab 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-admin-group-list';
 import {GrAdminGroupList} from './gr-admin-group-list';
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 cbac9de..34e8d24 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-admin-view';
 import {AdminSubsectionLink, GrAdminView} from './gr-admin-view';
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 d4b5f03..a30b0df 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-confirm-delete-item-dialog';
 import {GrConfirmDeleteItemDialog} from './gr-confirm-delete-item-dialog';
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 87916b6..d26df6e 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-create-change-dialog';
 import {GrCreateChangeDialog} from './gr-create-change-dialog';
diff --git a/polygerrit-ui/app/elements/admin/gr-create-change-dialog/gr-create-file-edit-dialog_test.ts b/polygerrit-ui/app/elements/admin/gr-create-change-dialog/gr-create-file-edit-dialog_test.ts
index e2da5d7..885e1cf 100644
--- a/polygerrit-ui/app/elements/admin/gr-create-change-dialog/gr-create-file-edit-dialog_test.ts
+++ b/polygerrit-ui/app/elements/admin/gr-create-change-dialog/gr-create-file-edit-dialog_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-create-file-edit-dialog';
 import {createChange} from '../../../test/test-data-generators';
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 c5fbde3..407d015 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-create-group-dialog';
 import {GrCreateGroupDialog} from './gr-create-group-dialog';
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 c16a108..5dc4e42 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-group-members';
 import {GrGroupMembers, ItemType} from './gr-group-members';
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 5cf71f8..aaf8dfc 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-group';
 import {GrGroup} from './gr-group';
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 46f6ac4..2909694 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-permission';
 import {GrPermission} from './gr-permission';
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 672d58e..fea0d58 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {ConfigParameterInfoType} from '../../../constants/constants';
 import '../../../test/common-test-setup';
 import './gr-plugin-config-array-editor';
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 495de52..c321abf 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-repo-access';
 import {GrRepoAccess} from './gr-repo-access';
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 af2831a..deec717 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-repo-commands';
 import {GrRepoCommands} from './gr-repo-commands';
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 5e25b33..3dd5e69 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-repo-detail-list';
 import {GrRepoDetailList} from './gr-repo-detail-list';
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 36674f5..d7377aa 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-repo-list';
 import {GrRepoList} from './gr-repo-list';
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 3dc6f1e..1691b88 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-repo-plugin-config';
 import {GrRepoPluginConfig} from './gr-repo-plugin-config';
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 a4e0f09..e33fd04 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-repo';
 import {GrRepo} from './gr-repo';
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 8066289..650876d 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-rule-editor';
 import {GrRuleEditor} from './gr-rule-editor';
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 15f022b..b91a0a0 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
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {createChange} from '../../../test/test-data-generators';
 import {
   NumericChangeId,
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 c65371b..df1b297 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
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {GrChangeListBulkVoteFlow} from './gr-change-list-bulk-vote-flow';
 import {
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 94ca74a..859a2ba 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
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {fixture, html, assert} from '@open-wc/testing';
 import {IronDropdownElement} from '@polymer/iron-dropdown';
 import {SinonStubbedMember} from 'sinon';
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 4f5a888..2722efe 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
 import {
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 d2f5fa2..c494448 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
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {fixture, html, assert} from '@open-wc/testing';
 import {SinonStubbedMember} from 'sinon';
 import {
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 694d953..75a5b5c8 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
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {
   GrChangeListSection,
   computeLabelShortcut,
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 2934772..087b8a8 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
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {fixture, html, assert} from '@open-wc/testing';
 import {IronDropdownElement} from '@polymer/iron-dropdown';
 import {SinonStubbedMember} from 'sinon';
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 93a530d..d69eac8 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-change-list-view';
 import {GrChangeListView} from './gr-change-list-view';
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 c53f813..30d3455 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-change-list';
 import {GrChangeList, computeRelativeIndex} from './gr-change-list';
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 01ce0b6..9b09c84 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-dashboard-view';
 import {GrDashboardView} from './gr-dashboard-view';
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 ebcec4b..e122fd3 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-change-actions';
 import {navigationToken} from '../../core/gr-navigation/gr-navigation';
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 9a78cd6..e96caa4 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
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-change-metadata';
 
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 7b9c291..ca3de4a 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import '../../edit/gr-edit-constants';
 import '../gr-thread-list/gr-thread-list';
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 3602ebc..e449332 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-confirm-abandon-dialog';
 import {GrConfirmAbandonDialog} from './gr-confirm-abandon-dialog';
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 891175f..61cc227 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {fixture, html, assert} from '@open-wc/testing';
 import '../../../test/common-test-setup';
 import {queryAndAssert} from '../../../utils/common-util';
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 ae55a4d..d3e48ca 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-confirm-cherrypick-dialog';
 import {
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 1c2a89d..ea58df9 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-confirm-rebase-dialog';
 import {GrConfirmRebaseDialog, RebaseChange} from './gr-confirm-rebase-dialog';
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 920ff00..ad19f85 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {fixture, html, assert} from '@open-wc/testing';
 import '../../../test/common-test-setup';
 import {createParsedChange} from '../../../test/test-data-generators';
diff --git a/polygerrit-ui/app/elements/change/gr-copy-links/gr-copy-links_test.ts b/polygerrit-ui/app/elements/change/gr-copy-links/gr-copy-links_test.ts
index 37dd9aa..f2c536b 100644
--- a/polygerrit-ui/app/elements/change/gr-copy-links/gr-copy-links_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-copy-links/gr-copy-links_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {fixture, html, assert} from '@open-wc/testing';
 import './gr-copy-links';
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 c730671..18da58d 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {
   createChange,
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 e6005c2..8bf316f 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-file-list-header';
 import {FilesExpandedState} from '../gr-file-list-constants';
diff --git a/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list_test.ts b/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list_test.ts
index ca7ab14..a375e1d 100644
--- a/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list_test.ts
+++ b/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import '../../shared/gr-date-formatter/gr-date-formatter';
 import './gr-file-list';
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 8752a6c..7129247 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-label-score-row';
 import {GrLabelScoreRow} from './gr-label-score-row';
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 1dbacc1..afd8ac2 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-message';
 import {
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 68fbe8b..d4c7b63 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
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-messages-list';
 import {CombinedMessage, GrMessagesList, TEST_ONLY} from './gr-messages-list';
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 4f951f3..504c8b5 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
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-reply-dialog';
 import {
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 7c8aece..883c5ba 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-reply-dialog';
 import {
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 f050ab50..0fcb83c 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-reviewer-list';
 import {mockPromise, queryAndAssert} from '../../../test/test-utils';
diff --git a/polygerrit-ui/app/elements/checks/gr-checks-fix-preview_test.ts b/polygerrit-ui/app/elements/checks/gr-checks-fix-preview_test.ts
index 21fa5d6..8a9997a 100644
--- a/polygerrit-ui/app/elements/checks/gr-checks-fix-preview_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-checks-fix-preview_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2024 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import './gr-checks-results';
 import {html} from 'lit';
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 e9fbeda..8e99c3c 100644
--- a/polygerrit-ui/app/elements/checks/gr-hovercard-run_test.ts
+++ b/polygerrit-ui/app/elements/checks/gr-hovercard-run_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import './gr-hovercard-run';
 import {fixture, html, assert} from '@open-wc/testing';
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 fff69ef..4f3b0fb 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-error-manager';
 import {
diff --git a/polygerrit-ui/app/elements/core/gr-notifications-prompt/gr-notifications-prompt_test.ts b/polygerrit-ui/app/elements/core/gr-notifications-prompt/gr-notifications-prompt_test.ts
index cbbcee0..c48946b 100644
--- a/polygerrit-ui/app/elements/core/gr-notifications-prompt/gr-notifications-prompt_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-notifications-prompt/gr-notifications-prompt_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-notifications-prompt';
 import {GrNotificationsPrompt} from './gr-notifications-prompt';
diff --git a/polygerrit-ui/app/elements/core/gr-router/gr-page_test.ts b/polygerrit-ui/app/elements/core/gr-router/gr-page_test.ts
index 729a15b..4e1f37d 100644
--- a/polygerrit-ui/app/elements/core/gr-router/gr-page_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-router/gr-page_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2023 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {html, assert, fixture, waitUntil} from '@open-wc/testing';
 import './gr-router';
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 4a78140..6a86ad1 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-router';
 import {Page, PageContext} from './gr-page';
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 bc8da05..62ef654 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-search-bar';
 import {GrSearchBar} from './gr-search-bar';
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 4331cf4..d72a85e 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
@@ -3,6 +3,7 @@
  * Copyright 2019 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-apply-fix-dialog';
 import {
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 eea8aaa..54a48b9 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-diff-host';
 import {
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
index 2d51eed..43dee0a 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-diff-mode-selector';
 import {GrDiffModeSelector} from './gr-diff-mode-selector';
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 96467b4..789c84d 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-diff-view';
 import {
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 65c6f1a..7aeda18 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import '../../shared/revision-info/revision-info';
 import './gr-patch-range-select';
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 ea5e9f3..c92f5bb 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-documentation-search';
 import {GrDocumentationSearch} from './gr-documentation-search';
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 aacbb36..bd6ec1cd 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-edit-controls';
 import {GrEditControls} from './gr-edit-controls';
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 bd27660..a406251 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-edit-file-controls';
 import {GrEditFileControls} from './gr-edit-file-controls';
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 e20d66d..a26eb42 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-editor-view';
 import {GrEditorView} from './gr-editor-view';
diff --git a/polygerrit-ui/app/elements/gr-app_test.ts b/polygerrit-ui/app/elements/gr-app_test.ts
index cd19872..7929d9b 100644
--- a/polygerrit-ui/app/elements/gr-app_test.ts
+++ b/polygerrit-ui/app/elements/gr-app_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../test/common-test-setup';
 import './gr-app';
 import {getAppContext} from '../services/app-context';
diff --git a/polygerrit-ui/app/elements/plugins/gr-attribute-helper/gr-attribute-helper_test.ts b/polygerrit-ui/app/elements/plugins/gr-attribute-helper/gr-attribute-helper_test.ts
index 5c15816..76b0a4d 100644
--- a/polygerrit-ui/app/elements/plugins/gr-attribute-helper/gr-attribute-helper_test.ts
+++ b/polygerrit-ui/app/elements/plugins/gr-attribute-helper/gr-attribute-helper_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {Polymer} from '@polymer/polymer/lib/legacy/polymer-fn';
 import {fixture, html, assert} from '@open-wc/testing';
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 cef6a8b..5164e98 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 * as sinon from 'sinon';
 import {assert} from '@open-wc/testing';
 import {HookApi, PluginElement} from '../../../api/hook';
 import {PluginApi} from '../../../api/plugin';
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 e0b792f..932dc96 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-plugin-host';
 import {GrPluginHost} from './gr-plugin-host';
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 8e7605d..80ae34d 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {fixture, html, assert} from '@open-wc/testing';
 import '../../../test/common-test-setup';
 import {stubElement} from '../../../test/test-utils';
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 5354ea5..e6c7100 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import '../../shared/gr-js-api-interface/gr-js-api-interface';
 import {GrPopupInterface} from './gr-popup-interface';
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 12321c2..fbcd494 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-email-editor';
 import {GrEmailEditor} from './gr-email-editor';
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 5be5b29..7192235 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-gpg-editor';
 import {
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 d52b423..e96fa39 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-identities';
 import {GrIdentities} from './gr-identities';
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 be81e4e..ec8a0e2 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-settings-view';
 import {GrSettingsView} from './gr-settings-view';
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 9528fb2..fddb603 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-ssh-editor';
 import {
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 c608656..e771a9d 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-watched-projects-editor';
 import {GrWatchedProjectsEditor} from './gr-watched-projects-editor';
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 552e321..e8d7dae 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-account-entry';
 import {GrAccountEntry} from './gr-account-entry';
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 eaf8974..887ef96 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-account-list';
 import {GrAccountList} from './gr-account-list';
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 6908e95..1fe860f 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-alert';
 import {GrAlert} from './gr-alert';
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 10ba5d0..b9063ba 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-autocomplete-dropdown';
 import {
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 0cef331..bf3ba66 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-autocomplete';
 import {AutocompleteSuggestion, GrAutocomplete} from './gr-autocomplete';
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 145e39d..f695ffa 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-button';
 import {addListener} from '@polymer/polymer/lib/utils/gestures';
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 b56fcfd..fb44c56 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-comment-thread';
 import {sortComments} from '../../../utils/comment-util';
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 fe19d9b..377e003 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-comment';
 import {AUTO_SAVE_DEBOUNCE_DELAY_MS, GrComment} from './gr-comment';
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 ef01dad..7e476eb 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-copy-clipboard';
 import {GrCopyClipboard} from './gr-copy-clipboard';
diff --git a/polygerrit-ui/app/elements/shared/gr-cursor-manager/gr-cursor-manager_test.ts b/polygerrit-ui/app/elements/shared/gr-cursor-manager/gr-cursor-manager_test.ts
index 81d2b45..b03a421 100644
--- a/polygerrit-ui/app/elements/shared/gr-cursor-manager/gr-cursor-manager_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-cursor-manager/gr-cursor-manager_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {fixture, html, assert} from '@open-wc/testing';
 import {AbortStop, CursorMoveResult} from '../../../api/core';
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 98f2d82..d6a01ab 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
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-date-formatter';
 import {GrDateFormatter} from './gr-date-formatter';
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 41fcfed..c4928d9 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-dialog';
 import {GrDialog} from './gr-dialog';
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 b1d4e36..2f656b2 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-download-commands';
 import {GrDownloadCommands} from './gr-download-commands';
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 c148a1b..fb150fc 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-dropdown-list';
 import {GrDropdownList} from './gr-dropdown-list';
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 e9ef52b..3a01748 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-dropdown';
 import {GrDropdown} from './gr-dropdown';
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 fe96d56..3d2469a 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-editable-content';
 import {GrEditableContent} from './gr-editable-content';
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 3bb058e..bb7989c 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-editable-label';
 import {GrEditableLabel} from './gr-editable-label';
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 d29d2a6..723267e 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
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {assert, fixture, html} from '@open-wc/testing';
 import {changeModelToken} from '../../../models/change/change-model';
diff --git a/polygerrit-ui/app/elements/shared/gr-hovercard-account/gr-hovercard-account-contents_test.ts b/polygerrit-ui/app/elements/shared/gr-hovercard-account/gr-hovercard-account-contents_test.ts
index 5afd53b..647282f 100644
--- a/polygerrit-ui/app/elements/shared/gr-hovercard-account/gr-hovercard-account-contents_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-hovercard-account/gr-hovercard-account-contents_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
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 d42dc7c..b2e412c 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import '../../change/gr-change-actions/gr-change-actions';
 import {query, queryAll, queryAndAssert} from '../../../test/test-utils';
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 ddba546..329d363 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
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-js-api-interface';
 import {EndpointType, GrPluginEndpoints} from './gr-plugin-endpoints';
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 b2ac2bf..3b07ddd 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {PLUGIN_LOADING_TIMEOUT_MS} from './gr-api-utils';
 import {PluginLoader} from './gr-plugin-loader';
diff --git a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-rest-api_test.ts b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-rest-api_test.ts
index 472093e..8b5ce6a 100644
--- a/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-rest-api_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-plugin-rest-api_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-js-api-interface';
 import {GrPluginRestApi} from './gr-plugin-rest-api';
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 8e4edd6..2758d21 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
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import '../../change/gr-reply-dialog/gr-reply-dialog';
 import {getAppContext} from '../../../services/app-context';
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 dad056b..6345754 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-label-info';
 import {
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 a8f6ff2..1a2d23c 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-labeled-autocomplete';
 import {GrLabeledAutocomplete} from './gr-labeled-autocomplete';
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 7e353f6..112ec78 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 * as sinon from 'sinon';
 import {assert} from '@open-wc/testing';
 import '../../../test/common-test-setup';
 import {waitEventLoop} from '../../../test/test-utils';
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 08572b6..3f9a32b 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-linked-chip';
 import {GrLinkedChip} from './gr-linked-chip';
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 5b1e162..c0d9755 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-list-view';
 import {GrListView} from './gr-list-view';
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 1cdb5c7..f627577 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-page-nav';
 import {GrPageNav} from './gr-page-nav';
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 6839431..24b377c 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-repo-branch-picker';
 import {GrRepoBranchPicker} from './gr-repo-branch-picker';
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 0f7acae..cea6704 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
@@ -3,6 +3,7 @@
  * Copyright 2024 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../../test/common-test-setup';
 import {
   SiteBasedCache,
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 4bb63ea..20f708e 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-select';
 import {fixture, html, assert} from '@open-wc/testing';
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 f489664..b2fed78 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
@@ -3,6 +3,7 @@
  * Copyright 2018 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-shell-command';
 import {GrShellCommand} from './gr-shell-command';
diff --git a/polygerrit-ui/app/elements/shared/gr-suggestion-textarea/gr-suggestion-textarea_test.ts b/polygerrit-ui/app/elements/shared/gr-suggestion-textarea/gr-suggestion-textarea_test.ts
index 3d36dfa..a6a1d83 100644
--- a/polygerrit-ui/app/elements/shared/gr-suggestion-textarea/gr-suggestion-textarea_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-suggestion-textarea/gr-suggestion-textarea_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-suggestion-textarea';
 import {GrSuggestionTextarea} from './gr-suggestion-textarea';
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 a9080e8..661515a 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
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-tooltip-content';
 import {GrTooltipContent} from './gr-tooltip-content';
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 581b577..62a1461 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
@@ -3,6 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {fixture, assert} from '@open-wc/testing';
 import {html} from 'lit';
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 a8cdff6..088dac6 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
@@ -3,6 +3,7 @@
  * Copyright 2019 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {CoverageType, Side} from '../../../api/diff';
 import {GrCoverageLayer, mergeRanges} from './gr-coverage-layer';
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 8d0050f..8eeaa84 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
@@ -3,6 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {
   GrDiffLineType,
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 70fece3..6f5674c 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import '../gr-diff/gr-diff';
 import './gr-diff-cursor';
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-annotation_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-annotation_test.ts
index 378c255..6ee5f18 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-annotation_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-highlight/gr-annotation_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {
   TEST_ONLY,
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 32decb1..e186b72 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-diff-highlight';
 import {getTextOffset} from './gr-range-normalizer';
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 9cc6a90..dd39aa5 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-diff-selection';
 import '../gr-diff/gr-diff';
diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff_test.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff_test.ts
index 5fa4788..ffb5c90 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2015 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import {
   createConfig,
diff --git a/polygerrit-ui/app/embed/diff/gr-focus-layer/gr-focus-layer_test.ts b/polygerrit-ui/app/embed/diff/gr-focus-layer/gr-focus-layer_test.ts
index f76ddef..9687ee8 100644
--- a/polygerrit-ui/app/embed/diff/gr-focus-layer/gr-focus-layer_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-focus-layer/gr-focus-layer_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2024 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 
 import {assert} from '@open-wc/testing';
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 338ac07..a7e215b 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import '../gr-diff/gr-diff-line';
 import './gr-ranged-comment-layer';
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 67836a4..5cc8409 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
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../../test/common-test-setup';
 import './gr-selection-action-box';
 import {GrSelectionActionBox} from './gr-selection-action-box';
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 221eada..1d8b4ed 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 * as sinon from 'sinon';
 import {assert} from '@open-wc/testing';
 import {DiffInfo, GrDiffLineType, Side} from '../../../api/diff';
 import {getAppContext} from '../../../services/app-context';
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 1ac9593..8f2c751 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
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {
   createAccountWithIdNameAndEmail,
   createChange,
diff --git a/polygerrit-ui/app/models/change/change-model_test.ts b/polygerrit-ui/app/models/change/change-model_test.ts
index bf7b9dc..e6175c0 100644
--- a/polygerrit-ui/app/models/change/change-model_test.ts
+++ b/polygerrit-ui/app/models/change/change-model_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {Subject} from 'rxjs';
 import {ChangeStatus} from '../../constants/constants';
 import '../../test/common-test-setup';
diff --git a/polygerrit-ui/app/models/checks/checks-model_test.ts b/polygerrit-ui/app/models/checks/checks-model_test.ts
index a8eda0f..fdaacd2 100644
--- a/polygerrit-ui/app/models/checks/checks-model_test.ts
+++ b/polygerrit-ui/app/models/checks/checks-model_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import './checks-model';
 import {
diff --git a/polygerrit-ui/app/models/config/config-model_test.ts b/polygerrit-ui/app/models/config/config-model_test.ts
index b78a933..bb6af87 100644
--- a/polygerrit-ui/app/models/config/config-model_test.ts
+++ b/polygerrit-ui/app/models/config/config-model_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2023 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import {assert} from '@open-wc/testing';
 import {getBaseUrl} from '../../utils/url-util';
diff --git a/polygerrit-ui/app/models/views/admin_test.ts b/polygerrit-ui/app/models/views/admin_test.ts
index 1cd1897..eab362a 100644
--- a/polygerrit-ui/app/models/views/admin_test.ts
+++ b/polygerrit-ui/app/models/views/admin_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {assert} from '@open-wc/testing';
 import '../../test/common-test-setup';
 import {assertRouteFalse, assertRouteState} from '../../test/test-utils';
diff --git a/polygerrit-ui/app/models/views/search_test.ts b/polygerrit-ui/app/models/views/search_test.ts
index ed6de419..0b0594f 100644
--- a/polygerrit-ui/app/models/views/search_test.ts
+++ b/polygerrit-ui/app/models/views/search_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {assert} from '@open-wc/testing';
 import {SinonStubbedMember} from 'sinon';
 import {
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 f50921e..28be742 100644
--- a/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts
+++ b/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2017 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import {Auth, AuthStatus} from './gr-auth_impl';
 import {SinonFakeTimers} from 'sinon';
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 91d742a..86e1cd1 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting_test.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import {
   GrReporting,
diff --git a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.ts b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.ts
index cb4a43d..204d626 100644
--- a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.ts
+++ b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2016 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import {
   addListenerForTest,
diff --git a/polygerrit-ui/app/services/gr-reviewer-suggestions-provider/gr-reviewer-suggestions-provider_test.ts b/polygerrit-ui/app/services/gr-reviewer-suggestions-provider/gr-reviewer-suggestions-provider_test.ts
index e96a2ad..0118e2e 100644
--- a/polygerrit-ui/app/services/gr-reviewer-suggestions-provider/gr-reviewer-suggestions-provider_test.ts
+++ b/polygerrit-ui/app/services/gr-reviewer-suggestions-provider/gr-reviewer-suggestions-provider_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2019 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import {GrReviewerSuggestionsProvider} from './gr-reviewer-suggestions-provider';
 import {getAppContext} from '../app-context';
diff --git a/polygerrit-ui/app/services/scheduler/retry-scheduler_test.ts b/polygerrit-ui/app/services/scheduler/retry-scheduler_test.ts
index 041aed2..ee02cfc 100644
--- a/polygerrit-ui/app/services/scheduler/retry-scheduler_test.ts
+++ b/polygerrit-ui/app/services/scheduler/retry-scheduler_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import {assertFails, waitEventLoop} from '../../test/test-utils';
 import {Scheduler} 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 e13cf19..cfcebc1 100644
--- a/polygerrit-ui/app/services/service-worker-installer_test.ts
+++ b/polygerrit-ui/app/services/service-worker-installer_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2022 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {getAppContext} from './app-context';
 import '../test/common-test-setup';
 import {ServiceWorkerInstaller} from './service-worker-installer';
diff --git a/polygerrit-ui/app/services/shortcuts/shortcuts-service_test.ts b/polygerrit-ui/app/services/shortcuts/shortcuts-service_test.ts
index 164000a..4421e47 100644
--- a/polygerrit-ui/app/services/shortcuts/shortcuts-service_test.ts
+++ b/polygerrit-ui/app/services/shortcuts/shortcuts-service_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2021 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import '../../test/common-test-setup';
 import {
   COMBO_TIMEOUT_MS,
diff --git a/polygerrit-ui/app/services/storage/gr-storage_test.ts b/polygerrit-ui/app/services/storage/gr-storage_test.ts
index 72878f8..6c22005 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 * as sinon from 'sinon';
 import {assert} from '@open-wc/testing';
 import {NumericChangeId} from '../../api/rest-api';
 import '../../test/common-test-setup';
diff --git a/polygerrit-ui/app/utils/async-util_test.ts b/polygerrit-ui/app/utils/async-util_test.ts
index afc16d3..4383cbd 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 * as sinon from 'sinon';
 import {assert} from '@open-wc/testing';
 import {SinonFakeTimers} from 'sinon';
 import '../test/common-test-setup';
diff --git a/polygerrit-ui/app/utils/date-util_test.ts b/polygerrit-ui/app/utils/date-util_test.ts
index 8d16655..45cdc25 100644
--- a/polygerrit-ui/app/utils/date-util_test.ts
+++ b/polygerrit-ui/app/utils/date-util_test.ts
@@ -3,6 +3,7 @@
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
+import * as sinon from 'sinon';
 import {Timestamp} from '../types/common';
 import '../test/common-test-setup';
 import {
diff --git a/polygerrit-ui/app/workers/service-worker-class_test.ts b/polygerrit-ui/app/workers/service-worker-class_test.ts
index 33a19d9..5368911 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 * as sinon from 'sinon';
 import {assert} from '@open-wc/testing';
 import {Timestamp} from '../api/rest-api';
 import '../test/common-test-setup';