consumer.spec.js

const path = require('path');
const chai = require('chai');
const chaiAsPromised = require('chai-as-promised');
const expect = chai.expect;
const { Pact, Matchers } = require('@pact-foundation/pact');
const LOG_LEVEL = process.env.LOG_LEVEL || 'TRACE';

chai.use(chaiAsPromised);

describe('Pact', () => {
  const provider = new Pact({
    consumer: 'e2e Consumer Example',
    provider: 'e2e Provider Example',
    // port: 1234, // You can set the port explicitly here or dynamically (see setup() below)
    log: path.resolve(process.cwd(), 'logs', 'mockserver-integration.log'),
    dir: path.resolve(process.cwd(), 'pacts'),
    logLevel: LOG_LEVEL,
    spec: 2,
  });

  // Alias flexible matchers for simplicity
  const { eachLike, like, term, iso8601DateTimeWithMillis } = Matchers;

  // Animal we want to match :)
  const suitor = {
    id: 2,
    available_from: '2017-12-04T14:47:18.582Z',
    first_name: 'Nanny',
    animal: 'goat',
    last_name: 'Doe',
    age: 27,
    gender: 'F',
    location: {
      description: 'Werribee Zoo',
      country: 'Australia',
      post_code: 3000,
    },
    eligibility: {
      available: true,
      previously_married: true,
    },
    interests: ['walks in the garden/meadow', 'parkour'],
  };

  const MIN_ANIMALS = 2;

  // Define animal payload, with flexible matchers
  //
  // This makes the test much more resilient to changes in actual data.
  // Here we specify the 'shape' of the object that we care about.
  // It is also import here to not put in expectations for parts of the
  // API we don't care about
  const animalBodyExpectation = {
    id: like(1),
    available_from: iso8601DateTimeWithMillis(),
    first_name: like('Billy'),
    last_name: like('Goat'),
    animal: like('goat'),
    age: like(21),
    gender: term({
      matcher: 'F|M',
      generate: 'M',
    }),
    location: {
      description: like('Melbourne Zoo'),
      country: like('Australia'),
      post_code: like(3000),
    },
    eligibility: {
      available: like(true),
      previously_married: like(false),
    },
    interests: eachLike('walks in the garden/meadow'),
  };

  // Define animal list payload, reusing existing object matcher
  const animalListExpectation = eachLike(animalBodyExpectation, {
    min: MIN_ANIMALS,
  });

  // Setup a Mock Server before unit tests run.
  // This server acts as a Test Double for the real Provider API.
  // We then call addInteraction() for each test to configure the Mock Service
  // to act like the Provider
  // It also sets up expectations for what requests are to come, and will fail
  // if the calls are not seen.
  before(() =>
    provider.setup().then((opts) => {
      // Get a dynamic port from the runtime
      process.env.API_HOST = `http://127.0.0.1:${opts.port}`;
    })
  );

  // After each individual test (one or more interactions)
  // we validate that the correct request came through.
  // This ensures what we _expect_ from the provider, is actually
  // what we've asked for (and is what gets captured in the contract)
  afterEach(() => provider.verify());

  // Configure and import consumer API
  // Note that we update the API endpoint to point at the Mock Service
  const {
    createMateForDates,
    suggestion,
    getAnimalById,
  } = require('../consumer');

  // Verify service client works as expected.
  //
  // Note that we don't call the consumer API endpoints directly, but
  // use unit-style tests that test the collaborating function behaviour -
  // we want to test the function that is calling the external service.
  describe('when a call to list all animals from the Animal Service is made', () => {
    describe('and the user is not authenticated', () => {
      before(() =>
        provider.addInteraction({
          state: 'is not authenticated',
          uponReceiving: 'a request for all animals',
          withRequest: {
            method: 'GET',
            path: '/animals/available',
          },
          willRespondWith: {
            status: 401,
          },
        })
      );

      it('returns a 401 unauthorized', () => {
        return expect(suggestion(suitor)).to.eventually.be.rejectedWith(
          'Unauthorized'
        );
      });
    });
    describe('and the user is authenticated', () => {
      describe('and there are animals in the database', () => {
        before(() =>
          provider.addInteraction({
            state: 'Has some animals',
            uponReceiving: 'a request for all animals',
            withRequest: {
              method: 'GET',
              path: '/animals/available',
              headers: {
                Authorization: like('Bearer token'),
              },
            },
            willRespondWith: {
              status: 200,
              headers: {
                'Content-Type': 'application/json; charset=utf-8',
              },
              body: animalListExpectation,
            },
          })
        );

        it('returns a list of animals', (done) => {
          const suggestedMates = suggestion(suitor);

          expect(suggestedMates).to.eventually.have.deep.property(
            'suggestions[0].score',
            94
          );
          expect(suggestedMates)
            .to.eventually.have.property('suggestions')
            .with.lengthOf(MIN_ANIMALS)
            .notify(done);
        });
      });
    });
  });

  describe('when a call to the Animal Service is made to retrieve a single animal by ID', () => {
    describe('and there is an animal in the DB with ID 1', () => {
      before(() =>
        provider.addInteraction({
          state: 'Has an animal with ID 1',
          uponReceiving: 'a request for an animal with ID 1',
          withRequest: {
            method: 'GET',
            path: term({ generate: '/animals/1', matcher: '/animals/[0-9]+' }),
            headers: {
              Authorization: like('Bearer token'),
            },
          },
          willRespondWith: {
            status: 200,
            headers: {
              'Content-Type': 'application/json; charset=utf-8',
            },
            body: animalBodyExpectation,
          },
        })
      );

      it('returns the animal', (done) => {
        const suggestedMates = getAnimalById(11);

        expect(suggestedMates)
          .to.eventually.have.deep.property('id', 1)
          .notify(done);
      });
    });

    describe('and there no animals in the database', () => {
      before(() =>
        provider.addInteraction({
          state: 'Has no animals',
          uponReceiving: 'a request for an animal with ID 100',
          withRequest: {
            method: 'GET',
            path: '/animals/100',
            headers: {
              Authorization: like('Bearer token'),
            },
          },
          willRespondWith: {
            status: 404,
          },
        })
      );

      it('returns a 404', (done) => {
        // uncomment below to test a failed verify
        // const suggestedMates = getAnimalById(123)
        const suggestedMates = getAnimalById(100);

        expect(suggestedMates).to.eventually.be.a('null').notify(done);
      });
    });
  });

  describe('when a call to the Animal Service is made to create a new mate', () => {
    before(() =>
      provider.addInteraction({
        uponReceiving: 'a request to create a new mate',
        state: 'is authenticated',
        withRequest: {
          method: 'POST',
          path: '/animals',
          body: like(suitor),
          headers: {
            'Content-Type': 'application/json; charset=utf-8',
            Authorization: like('Bearer token'),
          },
        },
        willRespondWith: {
          status: 200,
          headers: {
            'Content-Type': 'application/json; charset=utf-8',
          },
          body: like(suitor),
        },
      })
    );

    it('creates a new mate', (done) => {
      expect(createMateForDates(suitor)).to.eventually.be.fulfilled.notify(
        done
      );
    });
  });

  // Write pact files
  after(() => {
    return provider.finalize();
  });
});