Mock components, services and more out of annoying dependencies for simplification of Angular testing

ng-mocks facilitates Angular testing and helps to:

- mock Components, Directives, Pipes, Modules, Services and Tokens
- reduce boilerplate in tests
- access declarations via simple interface

The current version of the library has been tested and can be used with:

| angular | ng-mocks | jasmine | jest | ivy | standalone | signals | defer |
| ------: | :------: | :-----: | :--: | :-: | :--------: | :-----: | :---: |
| 20 | latest | yes | yes | yes | yes | no | no |
| 19 | latest | yes | yes | yes | yes | no | no |
| 18 | latest | yes | yes | yes | yes | no | no |
| 17 | latest | yes | yes | yes | yes | no | no |
| 16 | latest | yes | yes | yes | yes | no | |
| 15 | latest | yes | yes | yes | yes | | |
| 14 | latest | yes | yes | yes | yes | | |
| 13 | latest | yes | yes | yes | | | |
| 12 | latest | yes | yes | yes | | | |
| 11 | latest | yes | yes | yes | | | |
| 10 | latest | yes | yes | yes | | | |
| 9 | latest | yes | yes | yes | | | |
| 8 | latest | yes | yes | | | | |
| 7 | latest | yes | yes | | | | |
| 6 | latest | yes | yes | | | | |
| 5 | latest | yes | yes | | | | |

Important links

- Documentation with examples of Angular testing
- CHANGELOG
- GitHub repo
- NPM package

* Live example on CodeSandbox
* Live example on StackBlitz

- start a discussion on GitHub
- ask a question on Stackoverflow
- report an issue on GitHub
- chat on gitter

Very short introduction

Global configuration for mocks in src/test.ts.
In case of jest, src/setup-jest.ts / src/test-setup.ts should be used.

``ts title="src/test.ts"
// All methods in mock declarations and providers
// will be automatically spied on their creation.
// https://ng-mocks.sudo.eu/extra/auto-spy
ngMocks.autoSpy('jasmine'); // or jest

// ngMocks.defaultMock helps to customize mocks
// globally. Therefore, we can avoid copy-pasting
// among tests.
// https://ng-mocks.sudo.eu/api/ngMocks/defaultMock
ngMocks.defaultMock(AuthService, () => ({
isLoggedIn$: EMPTY,
currentUser$: EMPTY,
}));
`

An example of a spec for a profile edit component.

`ts title="src/profile.component.spec.ts"
// Let's imagine that there is a ProfileComponent
// and it has 3 text fields: email, firstName,
// lastName, and a user can edit them.
// In the following test suite, we would like to
// cover behavior of the component.
describe('profile:builder', () => {
// Helps to reset customizations after each test.
// Alternatively, you can enable
// automatic resetting in test.ts.
MockInstance.scope();

// Let's configure TestBed via MockBuilder.
// The code below says to mock everything in
// ProfileModule except ProfileComponent and
// ReactiveFormsModule.
beforeEach(() => {
// The result of MockBuilder should be returned.
// https://ng-mocks.sudo.eu/api/MockBuilder
return MockBuilder(
ProfileComponent,
ProfileModule,
).keep(ReactiveFormsModule);
// // or old fashion way
// return TestBed.configureTestingModule({
// imports: [
// MockModule(SharedModule), // mock
// ReactiveFormsModule, // real
// ],
// declarations: [
// ProfileComponent, // real
// MockPipe(CurrencyPipe), // mock
// MockDirective(HoverDirective), // mock
// ],
// providers: [
// MockProvider(AuthService), // mock
// ],
// }).compileComponents();
});

// A test to ensure that ProfileComponent
// can be created.
it('should be created', () => {
// MockRender is an advanced version of
// TestBed.createComponent.
// It respects all lifecycle hooks,
// onPush change detection, and creates a
// wrapper component with a template like
//
// and renders it.
// It also respects all lifecycle hooks.
// https://ng-mocks.sudo.eu/api/MockRender
const fixture = MockRender(ProfileComponent);

expect(
fixture.point.componentInstance,
).toEqual(assertion.any(ProfileComponent));
});

// A test to ensure that the component listens
// on ctrl+s hotkey.
it('saves on ctrl+s hot key', () => {
// A fake profile.
const profile = {
email: 'test2@email.com',
firstName: 'testFirst2',
lastName: 'testLast2',
};

// A spy to track save calls.
// MockInstance helps to configure mock
// providers, declarations and modules
// before their initialization and usage.
// https://ng-mocks.sudo.eu/api/MockInstance
const spySave = MockInstance(
StorageService,
'save',
jasmine.createSpy(), // or jest.fn()
);

// Renders
// .
// https://ng-mocks.sudo.eu/api/MockRender
const { point } = MockRender(
ProfileComponent,
{ profile }, // bindings
);

// Let's change the value of the form control
// for email addresses with a random value.
// ngMocks.change finds a related control
// value accessor and updates it properly.
// https://ng-mocks.sudo.eu/api/ngMocks/change
ngMocks.change(
'[name=email]', // css selector
'test3@em.ail', // an email address
);

// Let's ensure that nothing has been called.
expect(spySave).not.toHaveBeenCalled();

// Let's assume that there is a host listener
// for a keyboard combination of ctrl+s,
// and we want to trigger it.
// ngMocks.trigger helps to emit events via
// simple interface.
// https://ng-mocks.sudo.eu/api/ngMocks/trigger
ngMocks.trigger(point, 'keyup.control.s');

// The spy should be called with the user
// and the random email address.
expect(spySave).toHaveBeenCalledWith({
email: 'test3@em.ail',
firstName: profile.firstName,
lastName: profile.lastName,
});
});
});
`

Profit.

Extra

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Thank you!

P.S. Feel free to contact us if you need help.