File Content: plugin_loader.test.ts // Use the real plugin_loader (stubbed by default) jest.unmock('app/features/plugins/plugin_loader'); jest.mock('app/core/core', () => { return { coreModule: { directive: jest.fn(), }, }; }); import { AppPluginMeta, PluginMetaInfo, PluginType, AppPlugin } from '@grafana/data'; import { SystemJS } from '@grafana/runtime'; // Loaded after the `unmock` above import { importAppPlugin } from '../plugin_loader'; class MyCustomApp extends AppPlugin { initWasCalled = false; calledTwice = false; init(meta: AppPluginMeta) { this.initWasCalled = true; this.calledTwice = this.meta === meta; } } describe('Load App', () => { const app = new MyCustomApp(); const modulePath = 'http://localhost:3000/public/plugins/my-app-plugin/module.js'; // Hook resolver for tests const originalResolve = SystemJS.constructor.prototype.resolve; SystemJS.constructor.prototype.resolve = (x: unknown) => x; beforeAll(() => { SystemJS.set(modulePath, { plugin: app }); }); afterAll(() => { SystemJS.delete(modulePath); SystemJS.constructor.prototype.resolve = originalResolve; }); it('should call init and set meta', async () => { const meta: AppPluginMeta = { id: 'test-app', module: modulePath, baseUrl: 'xxx', info: {} as PluginMetaInfo, type: PluginType.app, name: 'test', }; // Check that we mocked the import OK const m = await SystemJS.import(modulePath); expect(m.plugin).toBe(app); const loaded = await importAppPlugin(meta); expect(loaded).toBe(app); expect(app.meta).toBe(meta); expect(app.initWasCalled).toBeTruthy(); expect(app.calledTwice).toBeFalsy(); const again = await importAppPlugin(meta); expect(again).toBe(app); expect(app.calledTwice).toBeTruthy(); }); }); Submit