Redoc dispose testcase

lib/components/Redoc/redoc.js

@@ -106,16 +106,22 @@ export default class Redoc extends BaseComponent {
   static dispose() {
     let dom = new BrowserDomAdapter();
     let el = dom.query('redoc');
-    let parent = el.parentElement;
-    let nextSibling = el.nextElementSibling;
+    let parent;
+    let nextSibling;
+    if (el) {
+      parent = el.parentElement;
+      nextSibling = el.nextElementSibling;
+    }
 
-    Redoc.appRef && Redoc.appRef.dispose();
+    if (Redoc.appRef) {
+      Redoc.appRef.dispose();
       Redoc.appRef = null;
 
       // Redoc dispose removes host element, so need to restore it
       el = dom.createElement('redoc');
       el.innerText = 'Loading...';
-    parent.insertBefore(el, nextSibling);
+      parent && parent.insertBefore(el, nextSibling);
+    }
   }
 }
 Redoc.parameters = Redoc.parameters.concat([[OptionsManager], [ElementRef], [BrowserDomAdapter]]);

lib/components/Redoc/redoc.spec.js

@@ -129,8 +129,59 @@ describe('Redoc init', () => {
       done.fail('Error handler should not been called');
     });
   });
+
+  describe('Redoc dispose', () => {
+    let builder;
+    let fixture;
+    let element;
+    let disposeSpy;
+    let dom = new BrowserDomAdapter();
+    beforeEachProviders(() => [
+        provide(SchemaManager, {useValue: new SchemaManager()}),
+        provide(BrowserDomAdapter, {useValue: new BrowserDomAdapter()}),
+        provide(OptionsManager, {useValue: optsMgr})
+    ]);
+    beforeEach(injectAsync([TestComponentBuilder, SchemaManager], (tcb, schemaMgr) => {
+      builder = tcb;
+      return schemaMgr.load('/tests/schemas/methods-list-component.json').then(() => null, (err) => { throw err; });
+    }));
+
+    beforeEach((done) => {
+      builder.createAsync(TestApp).then(_fixture => {
+        fixture = _fixture;
+        element = getChildDebugElement(fixture.debugElement, 'methods-list').nativeElement;
+        disposeSpy = jasmine.createSpy('spy');
+        Redoc.appRef = {
+          dispose: disposeSpy
+        };
+        fixture.detectChanges();
+        done();
+      }, err => { throw err; });
     });
 
+    afterEach(()=> {
+      fixture.destroy();
+      Redoc.appRef = null;
+    });
+
+    it('should call componentRef.dispose', () => {
+      Redoc.dispose();
+      expect(disposeSpy).toHaveBeenCalled();
+    });
+
+    it('should create new host element', () => {
+      element.parentElement.removeChild(element);
+      Redoc.dispose();
+      expect(dom.query('redoc')).not.toBeNull();
+      dom.query('redoc').should.not.be.equal(element);
+    });
+
+    it('should set to null appRef', () => {
+      Redoc.dispose();
+      expect(Redoc.appRef).toBeNull();
+    });
+  });
+});
 
 /** Test component that contains a Redoc. */
 @Component({selector: 'test-app'})