chore: make renderer lifecyle test more robust

 - the first assertion is that the view after init has been called. rather than assert it, just wait for it using an observable and avoid asserting about timing and implementation specific details of the system. Specifically this removes the assumption that `app.tick()` will advance time and call `ngAfterViewInit` on the component.

Author: justindujardin

Diff for: tests/app/tests/renderer-tests.ts

@@ -1,18 +1,20 @@
 // make sure you import mocha-config before @angular/core
-import {assert} from './test-config';
-import {Component, ComponentRef, ElementRef, NgZone, Renderer2, ViewChild} from '@angular/core';
-import {ProxyViewContainer} from 'ui/proxy-view-container';
-import {Red} from 'color/known-colors';
-import {dumpView} from './test-utils';
-import {LayoutBase} from 'ui/layouts/layout-base';
-import {StackLayout} from 'ui/layouts/stack-layout';
-import {ContentView} from 'ui/content-view';
-import {Button} from 'ui/button';
-import {registerElement} from 'nativescript-angular/element-registry';
-import * as button from 'tns-core-modules/ui/button';
-import * as view from 'tns-core-modules/ui/core/view';
-import {nTestBedAfterEach, nTestBedBeforeEach, nTestBedRender} from 'nativescript-angular/testing';
-import {ComponentFixture, TestBed} from '@angular/core/testing';
+import {assert} from "./test-config";
+import {Component, ComponentRef, ElementRef, NgZone, Renderer2, ViewChild} from "@angular/core";
+import {ProxyViewContainer} from "ui/proxy-view-container";
+import {Red} from "color/known-colors";
+import {dumpView} from "./test-utils";
+import {LayoutBase} from "ui/layouts/layout-base";
+import {StackLayout} from "ui/layouts/stack-layout";
+import {ContentView} from "ui/content-view";
+import {Button} from "ui/button";
+import {registerElement} from "nativescript-angular/element-registry";
+import * as button from "tns-core-modules/ui/button";
+import * as view from "tns-core-modules/ui/core/view";
+import {nTestBedAfterEach, nTestBedBeforeEach, nTestBedRender} from "nativescript-angular/testing";
+import {ComponentFixture, TestBed} from "@angular/core/testing";
+import {Observable} from "rxjs/Observable";
+import {ReplaySubject} from "rxjs/ReplaySubject";
 
 @Component({
     template: `<StackLayout><Label text="Layout"></Label></StackLayout>`
@@ -226,10 +228,10 @@ export class NgControlSettersCount {
 
     get buttons(): ElementRef[] { return [this.btn1, this.btn2, this.btn3, this.btn4]; }
 
-    isAfterViewInit: boolean = false;
+    ready$: Observable<boolean> = new ReplaySubject<boolean>(1);
 
     ngAfterViewInit() {
-        this.isAfterViewInit = true;
+        (this.ready$ as ReplaySubject<boolean>).next(true);
     }
 }
 
@@ -609,8 +611,7 @@ describe("Renderer attach/detach", () => {
     });
 });
 
-// TODO: I'm not sure about this lifecycle test.
-xdescribe("Renderer lifecycle", () => {
+describe("Renderer lifecycle", () => {
     let renderer: Renderer2 = null;
     beforeEach(nTestBedBeforeEach([ZonedRenderer, NgControlSettersCount]));
     afterEach(nTestBedAfterEach(false));
@@ -624,16 +625,28 @@ xdescribe("Renderer lifecycle", () => {
 
     it("view native setters are called once on startup", () => {
         const fixture = TestBed.createComponent(NgControlSettersCount);
-        fixture.detectChanges();
-        const componentRef: ComponentRef<NgControlSettersCount> = fixture.componentRef;
-        assert.isTrue(componentRef.instance.isAfterViewInit, "Expected the NgControlSettersCount to have passed its ngAfterViewInit.");
-        componentRef.instance.buttons.map(btn => btn.nativeElement).forEach(btn => {
-            assert.isTrue(btn.isLoaded, `Expected ${btn.id} to be allready loaded.`);
-            assert.isFalse(btn.isLayoutValid, `Expected ${btn.id}'s layout to be invalid.`);
-
-            assert.equal(btn.backgroundInternalSetNativeCount, 1, `Expected ${btn.id} backgroundInternalSetNativeCount to be called just once.`);
-            assert.equal(btn.fontInternalSetNativeCount, 1, `Expected ${btn.id} fontInternalSetNativeCount to be called just once.`);
-            assert.equal(btn.nativeBackgroundRedraws, 0, `Expected ${btn.id} nativeBackgroundRedraws to be called after its layout pass.`);
+        const component: NgControlSettersCount = fixture.componentInstance;
+        return component.ready$.subscribe(() => {
+            component.buttons.map(btn => btn.nativeElement).forEach(btn => {
+                assert.isTrue(btn.isLoaded, `Expected ${btn.id} to be loaded.`);
+                assert.isFalse(
+                    btn.isLayoutValid,
+                    `Expected ${btn.id}'s layout to be invalid because it is uninitialized.`
+                );
+
+                assert.equal(
+                    btn.backgroundInternalSetNativeCount, 1,
+                    `Expected ${btn.id} backgroundInternalSetNativeCount to be called just once.`
+                );
+                assert.equal(
+                    btn.fontInternalSetNativeCount, 1,
+                    `Expected ${btn.id} fontInternalSetNativeCount to be called just once.`
+                );
+                assert.equal(
+                    btn.nativeBackgroundRedraws, 0,
+                    `Expected ${btn.id} nativeBackgroundRedraws to be called after its layout pass.`
+                );
+            });
         });
     });
 });