test(core): add lazy-load-service.spec

npm/ng-packs/packages/core/src/lib/services/lazy-load.service.ts

@@ -1,5 +1,5 @@
-import { Inject, Injectable } from '@angular/core';
-import { Observable, ReplaySubject } from 'rxjs';
+import { Injectable } from '@angular/core';
+import { Observable, ReplaySubject, throwError } from 'rxjs';
 import { uuid } from '../utils';
 
 @Injectable({
@@ -16,7 +16,7 @@ export class LazyLoadService {
     position: InsertPosition = 'afterend',
   ): Observable<void> {
     if (!urlOrUrls && !content) {
-      return;
+      return throwError('Should pass url or content');
     } else if (!urlOrUrls && content) {
       urlOrUrls = [null];
     }

npm/ng-packs/packages/core/src/lib/tests/lazy-load.service.spec.ts

@@ -0,0 +1,92 @@
+import { createServiceFactory, SpectatorService } from '@ngneat/spectator/jest';
+import clone from 'just-clone';
+import { LazyLoadService } from '../services/lazy-load.service';
+import { catchError } from 'rxjs/operators';
+import { of } from 'rxjs';
+
+describe('LazyLoadService', () => {
+  let spectator: SpectatorService<LazyLoadService>;
+  let service: LazyLoadService;
+  const scriptElement = document.createElement('script');
+  const linkElement = document.createElement('link');
+  const styleElement = document.createElement('style');
+  const cloneDocument = clone(document);
+
+  const createService = createServiceFactory({ service: LazyLoadService });
+
+  beforeEach(() => {
+    spectator = createService();
+    service = spectator.service;
+  });
+
+  afterEach(() => (document = clone(cloneDocument)));
+
+  test('should load script with content just one time', done => {
+    const spy = jest.spyOn(document, 'createElement');
+    spy.mockReturnValue(scriptElement);
+
+    service.load('https://abp.io', 'script', 'test').subscribe(res => {
+      expect(document.querySelector('script[src="https://abp.io"][type="text/javascript"]').textContent).toMatch(
+        'test',
+      );
+    });
+
+    scriptElement.onload(null);
+
+    service.load('https://abp.io', 'script', 'test').subscribe(res => {
+      expect(document.querySelectorAll('script[src="https://abp.io"][type="text/javascript"]')).toHaveLength(1);
+      done();
+    });
+  });
+
+  test('should load style element', done => {
+    const spy = jest.spyOn(document, 'createElement');
+    spy.mockReturnValue(styleElement);
+
+    const content = '* { color: black; }';
+    service.load(null, 'style', content).subscribe(res => {
+      expect(document.querySelector('style').textContent).toMatch(content);
+      done();
+    });
+
+    styleElement.onload(null);
+  });
+
+  describe('style with url', () => {
+    beforeEach(() => {
+      const spy = jest.spyOn(document, 'createElement');
+      spy.mockReturnValue(linkElement);
+    });
+
+    test('should load an link element', done => {
+      service.load('https://abp.io', 'style').subscribe(res => {
+        expect(document.querySelector('link[type="text/css"][rel="stylesheet"][href="https://abp.io"]')).toBeTruthy();
+        done();
+      });
+
+      linkElement.onload(null);
+    });
+
+    test('should load link elements', done => {
+      service.load(['https://abp.io', 'https://volosoft.com'], 'style').subscribe(res => {
+        expect(document.querySelector('link[href="https://volosoft.com"]')).toBeTruthy();
+        done();
+      });
+
+      linkElement.onload(null);
+    });
+  });
+
+  test('should throw error when required parameters are null', done => {
+    service
+      .load(null, 'style')
+      .pipe(
+        catchError(err => {
+          expect(err).toBeTruthy();
+          done();
+          return of(null);
+        }),
+      )
+      .subscribe();
+  });
+});