Service TestBed

Custom test bed for testing Service.

Quick example

describe('AppService', () => {
  const tb = serviceTestBed(AppService, { httpTesting: true }); // 🛠️ Create the test bed and enable http testing

  it('should fetch cat fact', tb(({ service, http, rx }, done) => {
    const mockBody = { fact: 'string', length: 6 };

    rx.remind = service.getCatFact().subscribe({ // 🧯 Use rx.remind to auto unsubscribe after the end of the test
      next: (res) => {
        expect(res).toEqual(mockBody);
        done();
      },
    });

    http.emitSuccessResponse({ url: service.CAT_FACT_URL, body: mockBody }); // 🎭 Fake the http response of the request that matches the url
  }));
});

serviceTestBed(..)

Creates a specific test bed for service.

It returns a function to be used to wrap it's callback and from which you access tools (check ServiceTools).

describe('AppService', () => {
  const tb = serviceTestBed(AppService);

  it('should ', tb((tools) => { // 👈 tb function used here
    // ... expectations
  }));
});

tb function supports the jasmine DoneFn and async/await notation.

describe('AppService', () => {
  const tb = serviceTestBed(AppService);

  it('should ', tb(async (tools) => {
    // ... async expectations
  }));

  it('should ', tb((tools, done) => {
    // ... expectations
    done();
  }));
});

TestBed Options

describe('AppService', () => {
  const tb = serviceTestBed(AppService, {} /* 👈 here */);

  it('should ', tb(() => {
    // ... expectations
  }));
});

imports

Default : []

Imports dependencies for the described service.

It is often used for non-standalone component, because standalone component embed its own importations.

Example :

const tb = serviceTestBed(AppService, {
  imports: [SharedModule, MaterialModule],
});

providers

Default : []

List of providers to be available during tests for the described service.

Example :

const tb = serviceTestBed(AppService, {
  providers: [AuthService, { provide: StoreService, useClass: MockStoreService }],
});

httpTesting

Default : false

Enables HttpTestingTools.

verifyHttp

Default : true

When enabled, each assertion will end by HttpTestingController.verify().

warning

Works only if httpTesting is true, otherwise has no effect.

autoCompile

Default : true

Automatically compiles the custom test bed for each test.

checkCreate

Default : true

Automatically invokes the "should create" Angular test.

It checks if the provided described instance is truthy.

Assertion tools

The tb function provides ServiceTools.

describe('AppService', () => {
  const tb = serviceTestBed(AppService);

  it('should ', tb((tools /* 👈 here */) => {
    // ... expectations
  }));
});

ServiceTools extends BaseTools and HttpTestingTools.

service

The described service instance.

info

The instance is typed according to the passed service Type<T> in serviceTestBed(..).

Example :

it('should ', tb(({ service }) => {
  expect(service.prop).toEqual('foo');
}));

Assertion options

For specific test, you enable/disable options that override the test bed options.

describe('AppService', () => {
  const tb = serviceTestBed(AppService);

  it('should ', tb((tools) => {
    // ... expectations
  }, {} /* 👈 here */));
});

verifyHttp

Same as options verifyHttp but only for the current assertion.

ServiceTestBed

import(..)

Same as options imports but with chaining methods.

Example :

describe('AppService', () => {
  const tb = serviceTestBed(AppService)
    .import(SharedModule)
    .import([ThirdPartyModule, MaterialModule]);
});

provide(..)

Same as options providers but with chaining methods.

Example :

describe('AppService', () => {
  const tb = serviceTestBed(AppService)
    .provide(NotifService)
    .provide([StoreService, { provide: MY_TOKEN, useValue: mockValue }]);
});

inject(..)

Links an injected instance to a key and retrieve it into the enhanced tools by autocompletion.

describe('AppService', () => {
  const tb = serviceTestBed(AppService)
    .inject('auth', AuthService);

  it('should ', tb(({ injected: { auth } }) => {
    // ... expectations
  }));
});

setup(..)

Setups extra action using the enhanced tools.

Works only for beforeEach and afterEach.

describe('AppService', () => {
  const tb = serviceTestBed(AppService);

  beforeEach(tb.setup(({ service }) => {
    service.foo = true;
  }));
});

compile()

To be used when you need to do third party setups before compiling the custom test bed.

warning

It has to be used into beforeEach(..) and autoCompile must be set to false.

describe('AppService', () => {
  const tb = serviceTestBed(AppService, { autoCompile: false });

  beforeEach(async () => {
    // ... third party setup
    await tb.compile();
  });
});

itShouldCreateService(..)

Create the "should create" for the described service.

To be used when there are no apparent or relevant tests to be performed.

describe('AppService', () => {
  itShouldCreateService(AppService);
});