test(docs-infra): add missing tests for obserables and promises (#34537)

This commit adds missing tests for obserables and promises which
are both stand-alone mini-apps.

PR Close #34537

aio/content/examples/comparing-observables/src/observables.spec.ts

@@ -0,0 +1,26 @@
+import { docRegionChain, docRegionObservable, docRegionUnsubscribe } from './observables';
+
+describe('observables', () => {
+  it('should print 2', (doneFn: DoneFn) => {
+    const consoleLogSpy = spyOn(console, 'log');
+    const observable = docRegionObservable(console);
+    observable.subscribe(() => {
+      expect(consoleLogSpy).toHaveBeenCalledTimes(1);
+      expect(consoleLogSpy).toHaveBeenCalledWith(2);
+      doneFn();
+    });
+  });
+
+  it('should close the subscription', () => {
+    const subscription = docRegionUnsubscribe();
+    expect(subscription.closed).toBeTruthy();
+  });
+
+  it('should chain an observable', (doneFn: DoneFn) => {
+    const observable = docRegionChain();
+    observable.subscribe(value => {
+      expect(value).toBe(4);
+      doneFn();
+    });
+  });
+});

aio/content/examples/comparing-observables/src/observables.ts

@@ -1,20 +1,37 @@
-import { map } from 'rxjs/operators';
+// #docplaster
-import { Observable } from 'rxjs';
 
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+
+export function docRegionObservable(console: Console) {
   // #docregion observable
 
   // declare a publishing operation
   const observable = new Observable<number>(observer => {
     // Subscriber fn...
+    // #enddocregion observable
+    // The below code is used for unit testing only
+    observer.next(2);
+    // #docregion observable
   });
 
   // initiate execution
-observable.subscribe(() => {
+  observable.subscribe(value => {
     // observer handles notifications
+    // #enddocregion observable
+    // The below code is used for unit testing only
+    console.log(value);
+    // #docregion observable
   });
 
   // #enddocregion observable
+  return observable;
+}
 
+export function docRegionUnsubscribe() {
+  const observable = new Observable<number>(() => {
+    // Subscriber fn...
+  });
   // #docregion unsubscribe
 
   const subscription = observable.subscribe(() => {
@@ -24,17 +41,32 @@ const subscription = observable.subscribe(() => {
   subscription.unsubscribe();
 
   // #enddocregion unsubscribe
+  return subscription;
+}
 
-// #docregion error
+export function docRegionError() {
-
+  const observable = new Observable<number>(() => {
-observable.subscribe(() => {
+    // Subscriber fn...
-  throw Error('my error');
   });
 
+  // #docregion error
+  observable.subscribe(() => {
+    throw new Error('my error');
+  });
   // #enddocregion error
+}
 
+export function docRegionChain() {
+  let observable = new Observable<number>(observer => {
+    // Subscriber fn...
+    observer.next(2);
+  });
+
+  observable =
   // #docregion chain
 
   observable.pipe(map(v => 2 * v));
 
   // #enddocregion chain
+  return observable;
+}

aio/content/examples/comparing-observables/src/promises.spec.ts

@@ -0,0 +1,23 @@
+import { docRegionError, docRegionPromise } from './promises';
+
+describe('promises', () => {
+  it('should print 2', (doneFn: DoneFn) => {
+    const consoleLogSpy = spyOn(console, 'log');
+    const pr = docRegionPromise(console, 2);
+    pr.then((value) => {
+      expect(consoleLogSpy).toHaveBeenCalledTimes(1);
+      expect(consoleLogSpy).toHaveBeenCalledWith(2);
+      expect(value).toBe(4);
+      doneFn();
+    });
+  });
+
+  it('should throw an error', (doneFn: DoneFn) => {
+    const promise = docRegionError();
+    promise
+      .then(() => {
+        throw new Error('Promise should be rejected.');
+      },
+        () => doneFn());
+  });
+});

aio/content/examples/comparing-observables/src/promises.ts

@@ -1,25 +1,44 @@
+// #docplaster
+
+export function docRegionPromise(console: Console, inputValue: number) {
   // #docregion promise
   // initiate execution
-const promise = new Promise<number>((resolve, reject) => {
+  let promise = new Promise<number>((resolve, reject) => {
     // Executer fn...
+    // #enddocregion promise
+    // The below is used in the unit tests.
+    resolve(inputValue);
+    // #docregion promise
   });
-
+  // #enddocregion promise
+  promise =
+  // #docregion promise
   promise.then(value => {
     // handle result here
-});
-
     // #enddocregion promise
-
+    // The below is used in the unit tests.
+    console.log(value);
+    return value;
+    // #docregion promise
+  });
+  // #enddocregion promise
+  promise =
   // #docregion chain
-
   promise.then(v => 2 * v);
-
   // #enddocregion chain
 
+  return promise;
+}
+
+export function docRegionError() {
+  let promise = Promise.resolve();
+  promise =
   // #docregion error
 
   promise.then(() => {
-  throw Error('my error');
+    throw new Error('my error');
   });
 
   // #enddocregion error
+  return promise;
+}