"Error: No provider for router" while writing Karma-Jasmine unit test cases
I get the same kind of error and I want to share my solution to help others
The Error I get in Karma
error properties: Object({ ngTempTokenPath: null, ngTokenPath: [ 'RouterModule', 'Router', 'Function', 'Function' ] })
NullInjectorError: R3InjectorError(DynamicTestModule)[RouterModule -> Router -> Function -> Function]:
NullInjectorError: No provider for Function!
inventory-view.component.ts
@Component({
selector: 'app-inventory-view',
templateUrl: './inventory-view.component.html',
styleUrls: ['./inventory-view.component.scss'],
animations: []
})
export class InventoryViewComponent implements OnInit, AfterViewInit, OnDestroy {
constructor(
public router: Router, // <--- here was the problem
public activatedRoute: ActivatedRoute
) { }
In my test file
inventory-view.component.spec.ts
import { HttpClientModule } from '@angular/common/http';
import { waitForAsync, ComponentFixture, TestBed } from '@angular/core/testing';
import { RouterTestingModule } from '@angular/router/testing';
import { ActivatedRoute, convertToParamMap, Router } from '@angular/router';
const ActivatedRouteSpy = {
snapshot: {
paramMap: convertToParamMap({
some: 'some',
else: 'else',
})
},
queryParamMap: of(
convertToParamMap({
some: 'some',
else: 'else',
})
)
};
const RouterSpy = jasmine.createSpyObj(
'Router',
['navigate']
);
describe('InventoryViewComponent', () => {
let component: InventoryViewComponent;
let fixture: ComponentFixture<InventoryViewComponent>;
beforeEach(waitForAsync(() => {
TestBed.configureTestingModule({
imports: [
HttpClientModule,
RouterTestingModule,
],
declarations: [ InventoryViewComponent ],
providers: [
{ provide: ActivatedRoute, useValue: ActivatedRouteSpy },
{ provide: Router, useValue: RouterSpy }
]
})
.compileComponents();
}));
beforeEach(waitForAsync(() => {
fixture = TestBed.createComponent(InventoryViewComponent);
component = fixture.componentInstance;
fixture.detectChanges();
}));
it('should create', () => {
expect(component).toBeTruthy();
});
});
Add RouterTestingModule for configureTestingModule testCase
==> imports: [RouterTestingModule],
import {RouterTestingModule} from '@angular/router/testing';
beforeEach(() => {
TestBed.configureTestingModule({
imports: [RouterTestingModule], // <====
providers: [],
declarations: [],
});
});
You need to import RouterTestingModule when setting up the test module.
/* tslint:disable:no-unused-variable */
import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';
import { DebugElement } from '@angular/core';
import { RouterTestingModule } from '@angular/router/testing';
import { MyNewComponentComponent } from './my-new-component.component';
describe('MyNewComponentComponent', () => {
let component: MyNewComponentComponent;
let fixture: ComponentFixture<MyNewComponentComponent>;
beforeEach(async(() => {
TestBed.configureTestingModule({
imports: [RouterTestingModule],
declarations: [ MyNewComponentComponent ]
})
.compileComponents();
}));
beforeEach(() => {
fixture = TestBed.createComponent(MyNewComponentComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
it('should create', () => {
expect(component).toBeTruthy();
});
});
Edit: example with mock DummyService
/* tslint:disable:no-unused-variable */
import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';
import { DebugElement } from '@angular/core';
import { RouterTestingModule } from '@angular/router/testing';
import { MyNewComponentComponent } from './my-new-component.component';
// import the service
import { DummyService } from '../dummy.service';
// mock the service
class MockDummyService extends DummyService {
// mock everything used by the component
};
describe('MyNewComponentComponent', () => {
let component: MyNewComponentComponent;
let fixture: ComponentFixture<MyNewComponentComponent>;
beforeEach(async(() => {
TestBed.configureTestingModule({
imports: [RouterTestingModule],
declarations: [MyNewComponentComponent],
providers: [{
provide: DummyService,
useClass: MockDummyService
}]
})
.compileComponents();
}));
beforeEach(() => {
fixture = TestBed.createComponent(MyNewComponentComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
it('should create', () => {
expect(component).toBeTruthy();
});
});