chore: fix tests leaking overlay containers (#9076)

src/cdk/overlay/overlay-container.spec.ts

@@ -29,7 +29,7 @@ describe('OverlayContainer', () => {
     overlayRef.attach(fixture.componentInstance.templatePortal);
     fixture.detectChanges();
 
-    expect(document.querySelectorAll('.cdk-overlay-container'))
+    expect(document.querySelector('.cdk-overlay-container'))
         .not.toBeNull('Expected the overlay container to be in the DOM after opening an overlay');
 
     // Manually call `ngOnDestroy` because there is no way to force Angular to destroy an

src/lib/autocomplete/autocomplete.spec.ts

@@ -89,11 +89,12 @@ describe('MatAutocomplete', () => {
     return TestBed.createComponent(component);
   }
 
-  afterEach(() => {
-    if (overlayContainer) {
-      overlayContainer.ngOnDestroy();
-    }
-  });
+  afterEach(inject([OverlayContainer], (currentOverlayContainer: OverlayContainer) => {
+    // Since we're resetting the testing module in some of the tests,
+    // we can potentially have multiple overlay containers.
+    currentOverlayContainer.ngOnDestroy();
+    overlayContainer.ngOnDestroy();
+  }));
 
   describe('panel toggling', () => {
     let fixture: ComponentFixture<SimpleAutocomplete>;
@@ -598,6 +599,7 @@ describe('MatAutocomplete', () => {
     });
 
     it('should disable the input when used with a value accessor and without `matInput`', () => {
+      overlayContainer.ngOnDestroy();
       fixture.destroy();
       TestBed.resetTestingModule();
 

src/lib/menu/menu.spec.ts

@@ -72,9 +72,12 @@ describe('MatMenu', () => {
     })();
   }));
 
-  afterEach(() => {
+  afterEach(inject([OverlayContainer], (currentOverlayContainer: OverlayContainer) => {
+    // Since we're resetting the testing module in some of the tests,
+    // we can potentially have multiple overlay containers.
+    currentOverlayContainer.ngOnDestroy();
     overlayContainer.ngOnDestroy();
-  });
+  }));
 
   it('should open the menu as an idempotent operation', () => {
     const fixture = TestBed.createComponent(SimpleMenu);

src/lib/tooltip/tooltip.spec.ts

@@ -70,9 +70,12 @@ describe('MatTooltip', () => {
     })();
   }));
 
-  afterEach(() => {
+  afterEach(inject([OverlayContainer], (currentOverlayContainer: OverlayContainer) => {
+    // Since we're resetting the testing module in some of the tests,
+    // we can potentially have multiple overlay containers.
+    currentOverlayContainer.ngOnDestroy();
     overlayContainer.ngOnDestroy();
-  });
+  }));
 
   describe('basic usage', () => {
     let fixture: ComponentFixture<BasicTooltipDemo>;