diff --git a/polygerrit-ui/app/BUILD b/polygerrit-ui/app/BUILD
index 20d66a5..5f9c3c5 100644
--- a/polygerrit-ui/app/BUILD
+++ b/polygerrit-ui/app/BUILD
@@ -106,8 +106,6 @@
     "elements/change/gr-reply-dialog/gr-reply-dialog_html.ts",
     "elements/change/gr-reviewer-list/gr-reviewer-list_html.ts",
     "elements/change/gr-thread-list/gr-thread-list_html.ts",
-    "elements/checks/gr-hovercard-run_html.ts",
-    "elements/core/gr-main-header/gr-main-header_html.ts",
     "elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog_html.ts",
     "elements/diff/gr-diff-builder/gr-diff-builder-element_html.ts",
     "elements/diff/gr-diff-host/gr-diff-host_html.ts",
diff --git a/polygerrit-ui/app/elements/checks/gr-hovercard-run.ts b/polygerrit-ui/app/elements/checks/gr-hovercard-run.ts
index 1ae3e2b..2316a05 100644
--- a/polygerrit-ui/app/elements/checks/gr-hovercard-run.ts
+++ b/polygerrit-ui/app/elements/checks/gr-hovercard-run.ts
@@ -112,6 +112,10 @@
     if (!run) return true;
     return !run.checkLink && !run.checkDescription;
   }
+
+  _convertUndefined(value?: string) {
+    return value ?? '';
+  }
 }
 
 declare global {
diff --git a/polygerrit-ui/app/elements/checks/gr-hovercard-run_html.ts b/polygerrit-ui/app/elements/checks/gr-hovercard-run_html.ts
index 277bd16..5b2e24a 100644
--- a/polygerrit-ui/app/elements/checks/gr-hovercard-run_html.ts
+++ b/polygerrit-ui/app/elements/checks/gr-hovercard-run_html.ts
@@ -130,7 +130,7 @@
         <div hidden$="[[!run.statusLink]]" class="row">
           <div class="title">Status</div>
           <div>
-            <a href="[[run.statusLink]]" target="_blank"
+            <a href="[[_convertUndefined(run.statusLink)]]" target="_blank"
               ><iron-icon
                 aria-label="external link to check status"
                 class="small link"
@@ -202,7 +202,7 @@
         <div hidden$="[[!run.checkLink]]" class="row">
           <div class="title">Documentation</div>
           <div>
-            <a href="[[run.checkLink]]" target="_blank"
+            <a href="[[_convertUndefined(run.checkLink)]]" target="_blank"
               ><iron-icon
                 aria-label="external link to check documentation"
                 class="small link"
@@ -216,10 +216,7 @@
     </div>
     <template is="dom-repeat" items="[[computeActions(run)]]">
       <div class="action">
-        <gr-checks-action
-          event-target="[[_target]]"
-          action="[[item]]"
-        ></gr-checks-action>
+        <gr-checks-action action="[[item]]"></gr-checks-action>
       </div>
     </template>
   </div>
diff --git a/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.ts b/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.ts
index f7e61bf..fd7e25e 100644
--- a/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.ts
+++ b/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.ts
@@ -110,7 +110,7 @@
   }
 
   @property({type: String, notify: true})
-  searchQuery?: string;
+  searchQuery = '';
 
   @property({type: Boolean, reflectToAttribute: true})
   loggedIn?: boolean;
diff --git a/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.js b/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
similarity index 66%
rename from polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.js
rename to polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
index ae7e10c..71d378e 100644
--- a/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.js
+++ b/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
@@ -15,17 +15,28 @@
  * limitations under the License.
  */
 
-import '../../../test/common-test-setup-karma.js';
-import './gr-search-bar.js';
-import '../../../scripts/util.js';
-import {TestKeyboardShortcutBinder, stubRestApi} from '../../../test/test-utils.js';
-import {Shortcut} from '../../../mixins/keyboard-shortcut-mixin/keyboard-shortcut-mixin.js';
-import {_testOnly_clearDocsBaseUrlCache} from '../../../utils/url-util.js';
+import '../../../test/common-test-setup-karma';
+import './gr-search-bar';
+import '../../../scripts/util';
+import {GrSearchBar} from './gr-search-bar';
+import {
+  TestKeyboardShortcutBinder,
+  stubRestApi,
+} from '../../../test/test-utils';
+import {Shortcut} from '../../../mixins/keyboard-shortcut-mixin/keyboard-shortcut-mixin';
+import {_testOnly_clearDocsBaseUrlCache} from '../../../utils/url-util';
+import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
+import {
+  createChangeConfig,
+  createGerritInfo,
+  createServerInfo,
+} from '../../../test/test-data-generators';
+import {MergeabilityComputationBehavior} from '../../../constants/constants';
 
 const basicFixture = fixtureFromElement('gr-search-bar');
 
 suite('gr-search-bar tests', () => {
-  let element;
+  let element: GrSearchBar;
 
   suiteSetup(() => {
     const kb = TestKeyboardShortcutBinder.push();
@@ -46,26 +57,34 @@
     assert.equal(element._inputVal, 'foo');
   });
 
-  const getActiveElement = () => (document.activeElement.shadowRoot ?
-    document.activeElement.shadowRoot.activeElement :
-    document.activeElement);
+  const getActiveElement = () =>
+    document.activeElement!.shadowRoot
+      ? document.activeElement!.shadowRoot.activeElement
+      : document.activeElement;
 
   test('enter in search input fires event', done => {
     element.addEventListener('handle-search', () => {
       assert.notEqual(getActiveElement(), element.$.searchInput);
-      assert.notEqual(getActiveElement(), element.$.searchButton);
       done();
     });
     element.value = 'test';
-    MockInteractions.pressAndReleaseKeyOn(element.$.searchInput.$.input, 13,
-        null, 'enter');
+    MockInteractions.pressAndReleaseKeyOn(
+      element.$.searchInput.$.input,
+      13,
+      null,
+      'enter'
+    );
   });
 
   test('input blurred after commit', () => {
     const blurSpy = sinon.spy(element.$.searchInput.$.input, 'blur');
     element.$.searchInput.text = 'fate/stay';
-    MockInteractions.pressAndReleaseKeyOn(element.$.searchInput.$.input, 13,
-        null, 'enter');
+    MockInteractions.pressAndReleaseKeyOn(
+      element.$.searchInput.$.input,
+      13,
+      null,
+      'enter'
+    );
     assert.isTrue(blurSpy.called);
   });
 
@@ -73,8 +92,12 @@
     const searchSpy = sinon.spy();
     element.addEventListener('handle-search', searchSpy);
     element.value = '';
-    MockInteractions.pressAndReleaseKeyOn(element.$.searchInput.$.input, 13,
-        null, 'enter');
+    MockInteractions.pressAndReleaseKeyOn(
+      element.$.searchInput.$.input,
+      13,
+      null,
+      'enter'
+    );
     assert.isFalse(searchSpy.called);
   });
 
@@ -82,8 +105,12 @@
     const searchSpy = sinon.spy();
     element.addEventListener('handle-search', searchSpy);
     element.value = 'added:';
-    MockInteractions.pressAndReleaseKeyOn(element.$.searchInput.$.input, 13,
-        null, 'enter');
+    MockInteractions.pressAndReleaseKeyOn(
+      element.$.searchInput.$.input,
+      13,
+      null,
+      'enter'
+    );
     assert.isFalse(searchSpy.called);
   });
 
@@ -91,8 +118,12 @@
     const searchSpy = sinon.spy();
     element.addEventListener('handle-search', searchSpy);
     element.value = 'age:1week';
-    MockInteractions.pressAndReleaseKeyOn(element.$.searchInput.$.input, 13,
-        null, 'enter');
+    MockInteractions.pressAndReleaseKeyOn(
+      element.$.searchInput.$.input,
+      13,
+      null,
+      'enter'
+    );
     assert.isTrue(searchSpy.called);
   });
 
@@ -100,8 +131,12 @@
     const searchSpy = sinon.spy();
     element.addEventListener('handle-search', searchSpy);
     element.value = 'random:1week';
-    MockInteractions.pressAndReleaseKeyOn(element.$.searchInput.$.input, 13,
-        null, 'enter');
+    MockInteractions.pressAndReleaseKeyOn(
+      element.$.searchInput.$.input,
+      13,
+      null,
+      'enter'
+    );
     assert.isTrue(searchSpy.called);
   });
 
@@ -109,8 +144,12 @@
     const searchSpy = sinon.spy();
     element.addEventListener('handle-search', searchSpy);
     element.value = 'random:';
-    MockInteractions.pressAndReleaseKeyOn(element.$.searchInput.$.input, 13,
-        null, 'enter');
+    MockInteractions.pressAndReleaseKeyOn(
+      element.$.searchInput.$.input,
+      13,
+      null,
+      'enter'
+    );
     assert.isTrue(searchSpy.called);
   });
 
@@ -129,21 +168,23 @@
     });
 
     test('Autocompletes accounts', () => {
-      sinon.stub(element, 'accountSuggestions').callsFake(() =>
-        Promise.resolve([{text: 'owner:fred@goog.co'}])
-      );
+      sinon
+        .stub(element, 'accountSuggestions')
+        .callsFake(() => Promise.resolve([{text: 'owner:fred@goog.co'}]));
       return element._getSearchSuggestions('owner:fr').then(s => {
         assert.equal(s[0].value, 'owner:fred@goog.co');
       });
     });
 
     test('Autocompletes groups', done => {
-      sinon.stub(element, 'groupSuggestions').callsFake(() =>
-        Promise.resolve([
-          {text: 'ownerin:Polygerrit'},
-          {text: 'ownerin:gerrit'},
-        ])
-      );
+      sinon
+        .stub(element, 'groupSuggestions')
+        .callsFake(() =>
+          Promise.resolve([
+            {text: 'ownerin:Polygerrit'},
+            {text: 'ownerin:gerrit'},
+          ])
+        );
       element._getSearchSuggestions('ownerin:pol').then(s => {
         assert.equal(s[0].value, 'ownerin:Polygerrit');
         done();
@@ -151,13 +192,15 @@
     });
 
     test('Autocompletes projects', done => {
-      sinon.stub(element, 'projectSuggestions').callsFake(() =>
-        Promise.resolve([
-          {text: 'project:Polygerrit'},
-          {text: 'project:gerrit'},
-          {text: 'project:gerrittest'},
-        ])
-      );
+      sinon
+        .stub(element, 'projectSuggestions')
+        .callsFake(() =>
+          Promise.resolve([
+            {text: 'project:Polygerrit'},
+            {text: 'project:gerrit'},
+            {text: 'project:gerrittest'},
+          ])
+        );
       element._getSearchSuggestions('project:pol').then(s => {
         assert.equal(s[0].value, 'project:Polygerrit');
         done();
@@ -193,11 +236,15 @@
   ].forEach(mergeability => {
     suite(`mergeability as ${mergeability}`, () => {
       setup(done => {
-        stubRestApi('getConfig').returns(Promise.resolve({
-          change: {
-            mergeability_computation_behavior: mergeability,
-          },
-        }));
+        stubRestApi('getConfig').returns(
+          Promise.resolve({
+            ...createServerInfo(),
+            change: {
+              ...createChangeConfig(),
+              mergeability_computation_behavior: mergeability as MergeabilityComputationBehavior,
+            },
+          })
+        );
 
         element = basicFixture.instantiate();
         flush(done);
@@ -218,11 +265,15 @@
 
   suite('doc url', () => {
     setup(done => {
-      stubRestApi('getConfig').returns(Promise.resolve({
-        gerrit: {
-          doc_url: 'https://doc.com/',
-        },
-      }));
+      stubRestApi('getConfig').returns(
+        Promise.resolve({
+          ...createServerInfo(),
+          gerrit: {
+            ...createGerritInfo(),
+            doc_url: 'https://doc.com/',
+          },
+        })
+      );
 
       _testOnly_clearDocsBaseUrlCache();
       element = basicFixture.instantiate();
@@ -232,18 +283,17 @@
     test('compute help doc url with correct path', () => {
       assert.equal(element.docBaseUrl, 'https://doc.com/');
       assert.equal(
-          element._computeHelpDocLink(element.docBaseUrl),
-          'https://doc.com/user-search.html'
+        element._computeHelpDocLink(element.docBaseUrl),
+        'https://doc.com/user-search.html'
       );
     });
 
     test('compute help doc url fallback to gerrit url', () => {
       assert.equal(
-          element._computeHelpDocLink(),
-          'https://gerrit-review.googlesource.com/documentation/' +
+        element._computeHelpDocLink(null),
+        'https://gerrit-review.googlesource.com/documentation/' +
           'user-search.html'
       );
     });
   });
 });
-