fix(tree): not picking up indirect descendant node definitions (#17522)

Fixes the CDK tree not picking up definitions that aren't direct descendants.
Also fixes some tests that won't fail if the tree doesn't render anything.

src/cdk/tree/tree.spec.ts

@@ -95,9 +95,9 @@ describe('CdkTree', () => {
       it('with the right accessibility roles', () => {
         expect(treeElement.getAttribute('role')).toBe('tree');
 
-        getNodes(treeElement).forEach(node => {
-          expect(node.getAttribute('role')).toBe('treeitem');
-        });
+        expect(getNodes(treeElement).every(node => {
+          return node.getAttribute('role') === 'treeitem';
+        })).toBe(true);
       });
 
       it('with the right data', () => {
@@ -469,6 +469,15 @@ describe('CdkTree', () => {
         expect(changedNodes[2].getAttribute('initialIndex')).toBe(null);
       });
     });
+
+    it('should pick up indirect descendant node definitions', () => {
+      configureCdkTreeTestingModule([SimpleCdkTreeAppWithIndirectNodes]);
+      const fixture = TestBed.createComponent(SimpleCdkTreeAppWithIndirectNodes);
+      fixture.detectChanges();
+      treeElement = fixture.nativeElement.querySelector('cdk-tree');
+
+      expect(getNodes(treeElement).length).toBe(3);
+    });
   });
 
   describe('nested tree', () => {
@@ -502,9 +511,9 @@ describe('CdkTree', () => {
       it('with the right accessibility roles', () => {
         expect(treeElement.getAttribute('role')).toBe('tree');
 
-        getNodes(treeElement).forEach(node => {
-          expect(node.getAttribute('role')).toBe('treeitem');
-        });
+        expect(getNodes(treeElement).every(node => {
+          return node.getAttribute('role') === 'treeitem';
+        })).toBe(true);
       });
 
       it('with the right data', () => {
@@ -827,9 +836,9 @@ describe('CdkTree', () => {
         getNodes(initialNodes[0]).forEach((node: Element, index: number) => {
           node.setAttribute('initialIndex', `c${index}`);
         });
-        getNodes(initialNodes[0]).forEach((node, index) => {
-          expect(node.getAttribute('initialIndex')).toBe(`c${index}`);
-        });
+        expect(getNodes(initialNodes[0]).every((node, index) => {
+          return node.getAttribute('initialIndex') === `c${index}`;
+        })).toBe(true);
       }
 
       function mutateChildren(parent: TestData) {
@@ -965,10 +974,8 @@ describe('CdkTree', () => {
 
       const depthElements = Array.from(treeElement.querySelectorAll('.tree-test-level')!);
       const expectedLevels = ['0', '0', '1', '2', '0'];
-      depthElements.forEach((element, index) => {
-        const actualLevel = element.textContent!.trim();
-        expect(actualLevel).toBe(expectedLevels[index]);
-      });
+      const actualLevels = depthElements.map(element => element.textContent!.trim());
+      expect(actualLevels).toEqual(expectedLevels);
       expect(depthElements.length).toBe(5);
     });
   });
@@ -1158,6 +1165,22 @@ class SimpleCdkTreeApp {
   @ViewChildren(CdkTreeNodePadding) paddingNodes: QueryList<CdkTreeNodePadding<TestData>>;
 }
 
+@Component({
+  template: `
+    <cdk-tree [dataSource]="dataSource" [treeControl]="treeControl">
+      <ng-container [ngSwitch]="true">
+        <cdk-tree-node *cdkTreeNodeDef="let node" class="customNodeClass"
+                      cdkTreeNodePadding [cdkTreeNodePaddingIndent]="indent"
+                      cdkTreeNodeToggle>
+                      {{node.pizzaTopping}} - {{node.pizzaCheese}} + {{node.pizzaBase}}
+        </cdk-tree-node>
+      </ng-container>
+    </cdk-tree>
+  `
+})
+class SimpleCdkTreeAppWithIndirectNodes extends SimpleCdkTreeApp {
+}
+
 @Component({
   template: `
     <cdk-tree [dataSource]="dataSource" [treeControl]="treeControl">

src/cdk/tree/tree.ts

@@ -106,7 +106,11 @@ export class CdkTree<T> implements AfterContentChecked, CollectionViewer, OnDest
   @ViewChild(CdkTreeNodeOutlet, {static: true}) _nodeOutlet: CdkTreeNodeOutlet;
 
   /** The tree node template for the tree */
-  @ContentChildren(CdkTreeNodeDef) _nodeDefs: QueryList<CdkTreeNodeDef<T>>;
+  @ContentChildren(CdkTreeNodeDef, {
+    // We need to use `descendants: true`, because Ivy will no longer match
+    // indirect descendants if it's left as false.
+    descendants: true
+  }) _nodeDefs: QueryList<CdkTreeNodeDef<T>>;
 
   // TODO(tinayuangao): Setup a listener for scrolling, emit the calculated view to viewChange.
   //     Remove the MAX_VALUE in viewChange