Custom jest expect extension for GraphQL auth tests

auth.js

expect.extend({
  toBeForbidden(received) {

    const forbiddenErrorCode = 'FORBIDDEN';

    if (!received.errors || received.errors.length === 0) {
      return {
        message: `No errors in response`,
        pass: false
      }
    }

    const {extensions} = received.errors[0];

    if (!extensions) {
      return {
        message: `No extensions in response`,
        pass: false
      }
    }

    const {code} = extensions;

    if (forbiddenErrorCode === code) {
      return {
        message: 'Returns FORBIDDEN',
        pass: true
      }
    } else {
      return {
        message: `Expected ${forbiddenErrorCode}, received ${code}`,
        pass: false
      }
    }
  }
});

// Sample usage

// Helper method for checking forbidden mutations
  const expectForbiddenMutationForUser = async (mutation, params) => {
    const {server} = createServer({
      accessToken: 'ACCESS_TOKEN',
      user: {
        role: ROLE_USER
      }
    });

    const {mutate} = createTestClient(server);
    const res = await mutate({
      mutation,
      variables: params
    });


    expect(res).toBeForbidden();
  };

// Sample usage:
  it('cannot create new user while having USER role', async () => {
    await expectForbiddenMutationForUser(MUTATION_CREATE_USER, {
      userBody: {
        email: 'wayne@gmail.com',
        address1: 'addr1',
        city: 'city',
        state: 'CA',
        postalCode: '94608',
        country: 'USA',
        lastName: 'Gretzky',
        firstName: 'Wayne',
        birthDate: '2005-05-05',
        password: '123456'
      }
    })
  });