feat(ng-dev): AngularContext mocks performance.now

projects/ng-dev/README.md

@@ -10,7 +10,7 @@ yarn add -D @s-libs/ng-dev @s-libs/ng-core @s-libs/rxjs-core @s-libs/js-core @s-
 
 ## TSLint Config
 
-This library comes with a predefined `tslint.json` that track's the angular cli's config with these changes that we have found useful:
+This library comes with a predefined `tslint.json` that tracks the angular cli's config with these changes that we have found useful:
 
 - Disables rules that conflict with Prettier (via [tslint-config-prettier](https://github.com/prettier/tslint-config-prettier))
 - Allows using the `Function` type. Some of our libraries deal a lot with utilities that operate on functions, and using this type is very handy.

projects/ng-dev/src/lib/test-context/angular-context.spec.ts

@@ -201,6 +201,14 @@ describe('AngularContext', () => {
         expect(promiseResolvedBeforeChangeDetection).toBe(true);
       });
     });
+
+    it('advances `performance.now()` as well', () => {
+      ctx.run(() => {
+        const start = performance.now();
+        ctx.tick(10);
+        expect(performance.now()).toBe(start + 10);
+      });
+    });
   });
 
   describe('.init()', () => {

projects/ng-dev/src/lib/test-context/angular-context.ts

@@ -128,9 +128,7 @@ export class AngularContext<InitOptions = {}> {
       options = optionsOrTest;
     }
 
-    jasmine.clock().install();
-    fakeAsync(() => {
-      jasmine.clock().mockDate(this.startTime);
+    this.runWithMockedTime(() => {
       assert(test);
 
       this.init(options);
@@ -140,8 +138,7 @@ export class AngularContext<InitOptions = {}> {
       } finally {
         this.cleanUp();
       }
-    })();
-    jasmine.clock().uninstall();
+    });
   }
 
   /**
@@ -216,4 +213,19 @@ export class AngularContext<InitOptions = {}> {
   protected cleanUp(): void {
     discardPeriodicTasks();
   }
+
+  private runWithMockedTime(test: VoidFunction): void {
+    // https://github.com/angular/angular/issues/31677#issuecomment-573139551
+    const now = performance.now;
+    spyOn(performance, 'now').and.callFake(() => Date.now());
+
+    jasmine.clock().install();
+    fakeAsync(() => {
+      jasmine.clock().mockDate(this.startTime);
+      test();
+    })();
+    jasmine.clock().uninstall();
+
+    performance.now = now;
+  }
 }

projects/ng-dev/src/lib/test-context/index.ts

@@ -1,3 +1,3 @@
 export { AngularContext } from './angular-context';
-export { ComponentContext } from './component-context';
+export { ComponentContext, ComponentContextInit } from './component-context';
 export { Synchronized } from './synchronize';