Testing Components with TestBed

.gitignore

@@ -13,7 +13,7 @@ tags
 !/nativescript-angular/postinstall.js
 !/nativescript-angular/hooks/**/*.js
 !/nativescript-angular/gulpfile.js
-!/nativescript-angular/zone-js/**/*.js
+!/nativescript-angular/zone-js/dist/*.js
 
 .tscache
 .nvm

nativescript-angular/renderer.ts

@@ -5,7 +5,7 @@ import {
 } from "@angular/core";
 
 import { Device } from "tns-core-modules/platform";
-import { View } from "tns-core-modules/ui/core/view";
+import { View, getViewById } from "tns-core-modules/ui/core/view";
 import { addCss } from "tns-core-modules/application";
 import { topmost } from "tns-core-modules/ui/frame";
 import { profile } from "tns-core-modules/profiling";
@@ -110,6 +110,10 @@ export class NativeScriptRenderer extends Renderer2 {
     @profile
     selectRootElement(selector: string): NgView {
         traceLog("NativeScriptRenderer.selectRootElement: " + selector);
+        if (selector && selector[0] === "#") {
+            const result = getViewById(this.rootView, selector.slice(1));
+            return (result || this.rootView) as NgView;
+        }
         return this.rootView;
     }
 

nativescript-angular/testing/index.ts

@@ -0,0 +1,29 @@
+import { NgModule } from "@angular/core";
+import { TestComponentRenderer } from "@angular/core/testing";
+import { NativeScriptTestComponentRenderer } from "./src/nativescript_test_component_renderer";
+import { COMMON_PROVIDERS } from "../platform-common";
+import { APP_ROOT_VIEW } from "../platform-providers";
+import { testingRootView } from "./src/util";
+export * from "./src/util";
+
+/**
+ * Providers array is exported for cases where a custom module has to be constructed
+ * to test a particular piece of code. This can happen, for example, if you are trying
+ * to test dynamic component loading and need to specify an entryComponent for the testing
+ * module.
+ */
+export const NATIVESCRIPT_TESTING_PROVIDERS: any[] = [
+    COMMON_PROVIDERS,
+    {provide: APP_ROOT_VIEW, useFactory: testingRootView},
+    {provide: TestComponentRenderer, useClass: NativeScriptTestComponentRenderer},
+];
+
+/**
+ * NativeScript testing support module. Enables use of TestBed for angular components, directives,
+ * pipes, and services.
+ */
+@NgModule({
+    providers: NATIVESCRIPT_TESTING_PROVIDERS
+})
+export class NativeScriptTestingModule {
+}

nativescript-angular/testing/src/nativescript_test_component_renderer.ts

@@ -0,0 +1,24 @@
+import { Injectable } from "@angular/core";
+import { TestComponentRenderer } from "@angular/core/testing";
+import { topmost } from "tns-core-modules/ui/frame";
+import { LayoutBase } from "tns-core-modules/ui/layouts/layout-base";
+import { ProxyViewContainer } from "tns-core-modules/ui/proxy-view-container";
+
+/**
+ * A NativeScript based implementation of the TestComponentRenderer.
+ */
+@Injectable()
+export class NativeScriptTestComponentRenderer extends TestComponentRenderer {
+
+  insertRootElement(rootElId: string) {
+    const page = topmost().currentPage;
+
+    const layout = new ProxyViewContainer();
+    layout.id = rootElId;
+
+    const rootLayout = page.layoutView as LayoutBase;
+    rootLayout.addChild(layout);
+  }
+
+}
+

nativescript-angular/testing/src/util.ts

@@ -0,0 +1,165 @@
+
+import { View } from "tns-core-modules/ui/core/view";
+import { topmost } from "tns-core-modules/ui/frame";
+import { LayoutBase } from "tns-core-modules/ui/layouts/layout-base";
+import { ComponentFixture, TestBed } from "@angular/core/testing";
+import { NgModule, Type } from "@angular/core";
+import { NativeScriptModule } from "../../nativescript.module";
+import { platformBrowserDynamicTesting } from "@angular/platform-browser-dynamic/testing";
+import { NS_COMPILER_PROVIDERS } from "../../platform";
+import { NATIVESCRIPT_TESTING_PROVIDERS, NativeScriptTestingModule } from "../index";
+import { CommonModule } from "@angular/common";
+/**
+ * Get a reference to the root application view.
+ */
+export function testingRootView(): View {
+    return topmost().currentPage.content;
+}
+
+/**
+ * Declared test contexts. When the suite is done this map should be empty if all lifecycle
+ * calls have happened as expected.
+ * @private
+ */
+const activeTestFixtures: ComponentFixture<any>[][] = [];
+
+/**
+ * Return a promise that resolves after (durationMs) milliseconds
+ */
+export function promiseWait(durationMs: number) {
+    return () => new Promise((resolve) => setTimeout(() => resolve(), durationMs));
+}
+
+/**
+ * Perform basic TestBed environment initialization. Call this once in the main entry point to your tests.
+ */
+export function nTestBedInit() {
+    TestBed.initTestEnvironment(
+        NativeScriptTestingModule,
+        platformBrowserDynamicTesting(NS_COMPILER_PROVIDERS)
+    );
+}
+
+/**
+ * Helper for configuring a TestBed instance for rendering components for test. Ideally this
+ * would not be needed, and in truth it's just a wrapper to eliminate some boilerplate. It
+ * exists because when you need to specify `entryComponents` for a test the setup becomes quite
+ * a bit more complex than if you're just doing a basic component test.
+ *
+ * More about entryComponents complexity: https://github.com/angular/angular/issues/12079
+ *
+ * Use:
+ * ```
+ *   beforeEach(nTestBedBeforeEach([MyComponent,MyFailComponent]));
+ * ```
+ *
+ * **NOTE*** Remember to pair with {@see nTestBedAfterEach}
+ *
+ * @param components Any components that you will create during the test
+ * @param providers Any services your tests depend on
+ * @param imports Any module imports your tests depend on
+ * @param entryComponents Any entry components that your tests depend on
+ */
+export function nTestBedBeforeEach(
+    components: any[],
+    providers: any[] = [],
+    imports: any[] = [],
+    entryComponents: any[] = []) {
+    return (done) => {
+        activeTestFixtures.push([]);
+        // If there are no entry components we can take the simple path.
+        if (entryComponents.length === 0) {
+            TestBed.configureTestingModule({
+                declarations: [...components],
+                providers: [...providers],
+                imports: [NativeScriptModule, ...imports]
+            });
+        } else {
+            // If there are entry components, we have to reset the testing platform.
+            //
+            // There's got to be a better way... (o_O)
+            TestBed.resetTestEnvironment();
+            @NgModule({
+                declarations: entryComponents,
+                exports: entryComponents,
+                entryComponents: entryComponents
+            })
+            class EntryComponentsTestModule {
+            }
+            TestBed.initTestEnvironment(
+                EntryComponentsTestModule,
+                platformBrowserDynamicTesting(NS_COMPILER_PROVIDERS)
+            );
+            TestBed.configureTestingModule({
+                declarations: components,
+                imports: [
+                    NativeScriptModule, NativeScriptTestingModule, CommonModule,
+                    ...imports
+                ],
+                providers: [...providers, ...NATIVESCRIPT_TESTING_PROVIDERS],
+            });
+        }
+        TestBed.compileComponents()
+            .then(() => done())
+            .catch((e) => {
+                console.log(`Failed to instantiate test component with error: ${e}`);
+                console.log(e.stack);
+                done();
+            });
+    };
+}
+
+/**
+ * Helper for a basic component TestBed clean up.
+ * @param resetEnv When true the testing environment will be reset
+ * @param resetFn When resetting the environment, use this init function
+ */
+export function nTestBedAfterEach(resetEnv = true, resetFn = nTestBedInit) {
+    return () => {
+        if (activeTestFixtures.length === 0) {
+            throw new Error(
+                `There are no more declared fixtures.` +
+                `Did you call "nTestBedBeforeEach" and "nTestBedAfterEach" an equal number of times?`
+            );
+        }
+        const root = testingRootView() as LayoutBase;
+        const fixtures = activeTestFixtures.pop();
+        fixtures.forEach((fixture) => {
+            root.removeChild(fixture.nativeElement);
+            fixture.destroy();
+        });
+        TestBed.resetTestingModule();
+        if (resetEnv) {
+            TestBed.resetTestEnvironment();
+            resetFn();
+        }
+    };
+}
+
+/**
+ * Render a component using the TestBed helper, and return a promise that resolves when the
+ * ComponentFixture is fully initialized.
+ */
+export function nTestBedRender<T>(componentType: Type<T>): Promise<ComponentFixture<T>> {
+    const fixture = TestBed.createComponent(componentType);
+    fixture.detectChanges();
+    return fixture.whenRenderingDone()
+    // TODO(jd): it seems that the whenStable and whenRenderingDone utilities of ComponentFixture
+    //           do not work as expected. I looked at how to fix it and it's not clear how to provide
+    //           a {N} specific subclass, because ComponentFixture is newed directly rather than injected
+    // What to do about it? Maybe fakeAsync can help? For now just setTimeout for 100ms (x_X)
+        .then(promiseWait(100))
+        .then(() => {
+            const list = activeTestFixtures[activeTestFixtures.length - 1];
+            if (!list) {
+                console.warn(
+                    "nTestBedRender called without nTestBedBeforeEach/nTestBedAfter each. " +
+                    "You are responsible for calling 'fixture.destroy()' when your test is done " +
+                    "in order to clean up the components that are created."
+                );
+            } else {
+                list.push(fixture);
+            }
+            return fixture;
+        });
+}

nativescript-angular/zone-js/README.md

@@ -0,0 +1,10 @@
+Zone.js for NativeScript
+---
+
+Zone.js is a library that aims to intercept all asynchronous API calls made in an environment, in order 
+to wrap them into coherent execution contexts over time.
+
+NativeScript executes inside an environment that Zone.js is not designed to work in, so a custom Zone.js output 
+must be created.
+
+Find out more about this in the [Upgrading Zone.js document](../../doc/upgrading-zonejs.md)