[Testing] Trouble unit testing service with the Router injected in the constructor

I’m trying to test a service that has the application router injected in its constructor. Following Julie Ralph’s suggestions presented in AngularConnect conf 2015 (and her repository: https://github.com/juliemr/ng2-test-seed), I’m using Karma and Jasmine.

It follows the example service to be tested:

    import { Router } from 'angular2/router';

    export class ExampleService {
      constructor(router : Router) {
        this._router = router;
      }

      //...
    }

Right now, I’m just asserting the truth. It follows the service test:

    import { it, describe, expect, inject, beforeEachProviders, MockApplicationRef } from 'angular2/testing';
    import { ROUTER_PROVIDERS } from 'angular2/router';
    import { provide, ApplicationRef } from 'angular2/core';

    import { ExampleService } from 'example-service.js';

    describe('ExampleService', () => {
      beforeEachProviders(() => [
        ROUTER_PROVIDERS, ExampleService,
        provide(ApplicationRef, { useClass: MockApplicationRef })
      ]);

      it('should validate the truth', inject([ExampleService], (exService) => {
        expect(true).toBeTruthy();
      }));
    });

when I run the tests ( > karma start karma.config.js ), I get a TypeError: Cannot read property ‘length’ of null

Looking at the router.js source code, it looks like I should bootstrap at least one component before injecting router. Is there an easy way to inject the Router dependency in a test?

The Stacktrace:

ORIGINAL EXCEPTION: TypeError: Cannot read property ‘length’ of null ORIGINAL STACKTRACE: TypeError: Cannot read property ‘length’ of null at routerPrimaryComponentFactory (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/router.js:2963:27) at Injector._instantiate (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11920:19) at Injector._instantiateProvider (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11859:21) at Injector._new (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11849:19) at InjectorDynamicStrategy.getObjByKeyId (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11733:42) at Injector._getByKeyDefault (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12048:33) at Injector._getByKey (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12002:21) at Injector._getByDependency (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11990:21) at Injector._instantiate (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11887:32) at Injector._instantiateProvider (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11859:21) at Injector._new (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11849:19) at InjectorDynamicStrategy.getObjByKeyId (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11733:42) at Injector._getByKeyDefault (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12048:33) at Injector._getByKey (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12002:21) at Injector._getByDependency (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11990:21) at Injector._instantiate (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11887:32) at Injector._instantiateProvider (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11859:21) at Injector._new (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11849:19) at InjectorDynamicStrategy.getObjByKeyId (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11733:42) at Injector._getByKeyDefault (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12048:33) at Injector._getByKey (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12002:21) at Injector._getByDependency (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11990:21) at Injector._instantiate (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11887:32) at Injector._instantiateProvider (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11859:21) at Injector._new (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11849:19) at InjectorDynamicStrategy.getObjByKeyId (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11733:42) at Injector._getByKeyDefault (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12048:33) at Injector._getByKey (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:12002:21) at Injector.get (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2.js:11804:19) at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2477:25 at Array.map (native) at Array.map (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/es6-shim/es6-shim.js:1113:14) at FunctionWithParamTokens.execute (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2476:33) at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2601:25 at Zone.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/angular2-polyfills.js:138:17) at Zone.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2544:30) at runInTestZone (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2588:23) at Object.<anonymous> (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/angular2/bundles/testing.dev.js:2600:33) at attemptAsync (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1819:24) at QueueRunner.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1774:9) at QueueRunner.execute (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1762:10) at Spec.Env.queueRunnerFactory (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:627:35) at Spec.execute (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:353:10) at Object.fn (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:2360:37) at attemptAsync (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1819:24) at QueueRunner.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1774:9) at QueueRunner.execute (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1762:10) at Env.queueRunnerFactory (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:627:35) at Object.fn (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:2345:13) at attemptAsync (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1819:24) at QueueRunner.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1774:9) at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1801:16 at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1745:9 at queueRunnerFactory.onComplete (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:2348:17) at QueueRunner.clearStack (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:605:9) at QueueRunner.run (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1784:12) at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1801:16 at C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:1745:9 at complete (C:/Users/LSANTOS/Desktop/ng2-test-seed/node_modules/jasmine-core/lib/jasmine-core/jasmine.js:365:9)

[stevefarwell]

@mohammedzamakhan I guess I should re-phrase my question. Now that Angular 2 has it’s final release and ROUTER_PRIMARY_COMPONENT is no longer in ‘@angular/router’, @brandonroberts is there an update to your fix?

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