fix(aio): header click should always toggle expand/collapse (#16439)

Also adds class tests for this NavItemComponent.
Not (yet) testing effects on the templated HTML

aio/src/app/layout/nav-item/nav-item.component.html

@@ -1,6 +1,6 @@
 <div *ngIf="!node.children">
   <a href="{{node.url}}" [ngClass]="classes" title="{{node.tooltip}}"
-    (click)="itemClicked()" class="vertical-menu-item">
+    class="vertical-menu-item">
     {{node.title}}
   </a>
 </div>

aio/src/app/layout/nav-item/nav-item.component.spec.ts

@@ -0,0 +1,159 @@
+
+import { SimpleChange, SimpleChanges } from '@angular/core';
+
+import { NavItemComponent } from './nav-item.component';
+import { NavigationNode } from 'app/navigation/navigation.model';
+
+// Testing the component class behaviors, independent of its template
+// No dependencies. Just new it and test :)
+// Let e2e tests verify how it displays.
+describe('NavItemComponent (class-only)', () => {
+
+  let component: NavItemComponent;
+
+  let selectedNodes: NavigationNode[];
+  let setClassesSpy: jasmine.Spy;
+
+  function initialize(nd: NavigationNode) {
+    component.node = nd;
+    onChanges(); // Angular calls when initializing the component
+  }
+
+  // Enough to triggers component's ngOnChange method
+  function onChanges() {
+    component.ngOnChanges({node: <SimpleChange><any> 'anything' });
+  }
+
+  beforeEach(() => {
+
+    component = new NavItemComponent();
+    setClassesSpy = spyOn(component, 'setClasses').and.callThrough();
+
+    // Selected nodes is the selected node and its header ancestors
+    selectedNodes = [
+      { title: 'a' },           // selected node: an item or a header
+      { title: 'parent' },      // selected node's header parent
+      { title: 'grandparent' }, // selected node's header grandparent
+    ];
+    component.selectedNodes = selectedNodes;
+  });
+
+  describe('should have expected classes when initialized', () => {
+    it('with selected node', () => {
+      initialize(selectedNodes[0]);
+      expect(component.classes).toEqual(
+        // selecting the current node has no effect on expanded state,
+        // even if current node is a header.
+        { 'level-1': true, collapsed: true, expanded: false, selected: true}
+      );
+    });
+
+    it('with selected node ancestor', () => {
+      initialize(selectedNodes[1]);
+      expect(component.classes).toEqual(
+        // ancestor is a header and should be expanded
+        { 'level-1': true, collapsed: false, expanded: true, selected: true}
+      );
+    });
+
+    it('with other than a selected node or ancestor', () => {
+      initialize({ title: 'x' });
+      expect(component.classes).toEqual(
+        { 'level-1': true, collapsed: true, expanded: false, selected: false}
+      );
+    });
+  });
+
+  describe('when becomes a non-selected node', () => {
+
+    // this node won't be the selected node when ngOnChanges() called
+    beforeEach(() => component.node = { title: 'x' });
+
+    it('should collapse if previously expanded', () => {
+      component.isExpanded = true;
+      onChanges();
+      expect(component.isExpanded).toBe(false, 'becomes collapsed');
+    });
+
+    it('should de-select if previously selected', () => {
+      component.isSelected = true;
+      onChanges();
+      expect(component.isSelected).toBe(false, 'becomes de-selected');
+    });
+  });
+
+  describe('when becomes a selected node', () => {
+
+    // this node will be the selected node when ngOnChanges() called
+    beforeEach(() => component.node = selectedNodes[0]);
+
+    it('should select when previously not selected', () => {
+      component.isSelected = false;
+      onChanges();
+      expect(component.isSelected).toBe(true, 'becomes selected');
+    });
+
+    it('should leave the expanded/collapsed state untouched', () => {
+      component.isExpanded = false;
+      onChanges();
+      expect(component.isExpanded).toBe(false, 'remains false');
+
+      component.isExpanded = true;
+      onChanges();
+      expect(component.isExpanded).toBe(true, 'remains true');
+    });
+  });
+
+  describe('when becomes a selected ancestor node', () => {
+
+    // this node will be a selected node ancestor header when ngOnChanges() called
+    beforeEach(() => component.node = selectedNodes[2]);
+
+    it('should select when previously not selected', () => {
+      component.isSelected = false;
+      onChanges();
+      expect(component.isSelected).toBe(true, 'becomes selected');
+    });
+
+    it('should always expand this header', () => {
+      component.isExpanded = false;
+      onChanges();
+      expect(component.isExpanded).toBe(true, 'becomes expanded');
+
+      component.isExpanded = false;
+      onChanges();
+      expect(component.isExpanded).toBe(true, 'stays expanded');
+    });
+  });
+
+  describe('when headerClicked()', () => {
+    // current node doesn't matter in these tests.
+
+    it('should expand when headerClicked() and previously collapsed', () => {
+      component.isExpanded = false;
+      component.headerClicked();
+      expect(component.isExpanded).toBe(true, 'should be expanded');
+    });
+
+    it('should collapse when headerClicked() and previously expanded', () => {
+      component.isExpanded = true;
+      component.headerClicked();
+      expect(component.isExpanded).toBe(false, 'should be collapsed');
+    });
+
+    it('should not change isSelected when headerClicked()', () => {
+      component.isSelected = true;
+      component.headerClicked();
+      expect(component.isSelected).toBe(true, 'remains selected');
+
+      component.isSelected = false;
+      component.headerClicked();
+      expect(component.isSelected).toBe(false, 'remains not selected');
+    });
+
+    it('should set classes', () => {
+      component.headerClicked();
+      expect(setClassesSpy).toHaveBeenCalled();
+    });
+  });
+});

aio/src/app/layout/nav-item/nav-item.component.ts

@@ -1,5 +1,5 @@
 import { Component, Input, OnChanges, SimpleChanges } from '@angular/core';
-import { NavigationNode } from 'app/navigation/navigation.service';
+import { NavigationNode } from 'app/navigation/navigation.model';
 
 @Component({
   selector: 'aio-nav-item',
@@ -16,8 +16,9 @@ export class NavItemComponent implements OnChanges {
 
   ngOnChanges(changes: SimpleChanges) {
     if (changes['selectedNodes'] || changes['node']) {
-      this.isSelected = this.selectedNodes.indexOf(this.node) !== -1;
-      this.isExpanded = this.isSelected;
+      const ix = this.selectedNodes.indexOf(this.node);
+      this.isSelected = ix !== -1;
+      if (ix !== 0) { this.isExpanded = this.isSelected; }
     }
     this.setClasses();
   }
@@ -31,11 +32,6 @@ export class NavItemComponent implements OnChanges {
     };
   }
 
-  itemClicked() {
-    this.isExpanded = true;
-    this.isSelected = !!this.node;
-  }
-
   headerClicked() {
     this.isExpanded = !this.isExpanded;
     this.setClasses();

aio/src/app/layout/nav-menu/nav-menu.component.spec.ts

@@ -4,7 +4,7 @@ import { NavigationNode } from 'app/navigation/navigation.service';
 // Testing the component class behaviors, independent of its template
 // No dependencies, no life-cycle hooks. Just new it and test :)
 // Let e2e tests verify how it displays.
-describe('NavMenuComponent', () => {
+describe('NavMenuComponent (class-only)', () => {
   it('should filter out hidden nodes', () => {
     const component = new NavMenuComponent();
     const nodes: NavigationNode[] =