How to mock Pipe when testing Component

You can add your mockpipes in the declarations of the TestBed:

TestBed.configureTestingModule({             declarations: [                 AppComponent,                 MockPipe             ],            ...

The MockPipe needs to have the @Pipe decorator with the original name.

import {Pipe, PipeTransform} from '@angular/core';@Pipe({name: 'pipename'})class MockPipe implements PipeTransform {    transform(value: number): number {        //Do stuff here, if you want        return value;    }}

To stub the pipe, use Dinistro's answer. To spy on the pipe, you can complement that with the following:

let pipeSpy: jasmine.Spy;beforeEach(() => {    TestBed.configureTestingModule...    pipeSpy = spyOn(MockPipe.prototype, 'transform');};it('should do whatever', () => {    doYourStuff();    expect(pipeSpy).toHaveBeenCalled();}

If you want reusable util function for mocking pipes, you can try this option:

export function mockPipe(options: Pipe): Pipe {    const metadata: Pipe = {      name: options.name    };    return <any>Pipe(metadata)(class MockPipe {});}

And then just call this function inside the TestBed declarations array:

TestBed.configureTestingModule({    declarations: [        SomeComponent,        mockPipe({ name: 'myPipe' }),        mockPipe({ name: 'myOtherPipe' })    ],    // ...}).compileComponents();