angular · alan-agius4 · May 15, 2020 · May 15, 2020 · May 15, 2020 · May 18, 2020
diff --git a/.circleci/config.yml b/.circleci/config.yml
@@ -848,9 +848,12 @@ workflows:
             - build-npm-packages
             - build-ivy-npm-packages
             - legacy-unit-tests-saucelabs
-      - components-repo-unit-tests:
-          requires:
-            - build-npm-packages
+      # The below 'components-repo-unit-tests' is disabled until the Components team support building and testing their
+      # repo with TypeScript 3.9. The TS 3.9 update is being done in https://github.com/angular/components/pull/19336.
+      # We should re-enable this CI job, when the mentioned PR gets merged.
+      # - components-repo-unit-tests:
+      #     requires:
+      #       - build-npm-packages
       - test_zonejs:
           requires:
             - setup

diff --git a/aio/src/app/layout/doc-viewer/doc-viewer.component.spec.ts b/aio/src/app/layout/doc-viewer/doc-viewer.component.spec.ts
@@ -45,7 +45,7 @@ describe('DocViewerComponent', () => {
     let renderSpy: jasmine.Spy;
 
     const setCurrentDoc = (newDoc: TestParentComponent['currentDoc']) => {
-      parentComponent.currentDoc = newDoc && {id: 'fizz/buzz', ...newDoc};
+      parentComponent.currentDoc = newDoc;
       parentFixture.detectChanges();  // Run change detection to propagate the new doc to `DocViewer`.
       safeFlushAsapScheduler();  // Flush `asapScheduler` to trigger `DocViewer#render()`.
     };

diff --git a/aio/src/app/layout/doc-viewer/doc-viewer.component.ts b/aio/src/app/layout/doc-viewer/doc-viewer.component.ts
@@ -189,14 +189,16 @@ export class DocViewerComponent implements OnDestroy {
       const seconds = Number(cssValue.replace(/s$/, ''));
       return 1000 * seconds;
     };
+
+    // Some properties are not assignable and thus cannot be animated.
+    // Example methods, readonly and CSS properties:
+    // "length", "parentRule", "getPropertyPriority", "getPropertyValue", "item", "removeProperty", "setProperty"
+    type StringValueCSSStyleDeclaration
+      = Exclude<{ [K in keyof CSSStyleDeclaration]: CSSStyleDeclaration[K] extends string ? K : never }[keyof CSSStyleDeclaration], number>;
     const animateProp =
-        (elem: HTMLElement, prop: keyof CSSStyleDeclaration, from: string, to: string, duration = 200) => {
+        (elem: HTMLElement, prop: StringValueCSSStyleDeclaration, from: string, to: string, duration = 200) => {
           const animationsDisabled = !DocViewerComponent.animationsEnabled
                                      || this.hostElement.classList.contains(NO_ANIMATIONS);
-          if (prop === 'length' || prop === 'parentRule') {
-            // We cannot animate length or parentRule properties because they are readonly
-            return this.void$;
-          }
           elem.style.transition = '';
           return animationsDisabled
               ? this.void$.pipe(tap(() => elem.style[prop] = to))

diff --git a/integration/typings_test_ts38/include-all.ts b/integration/typings_test_ts38/include-all.ts
diff --git a/integration/typings_test_ts38/package.json b/integration/typings_test_ts38/package.json
diff --git a/integration/typings_test_ts38/tsconfig.json b/integration/typings_test_ts38/tsconfig.json