tests

// Chai is a commonly used library for creating unit test suites. It is easily extended with plugins.
import { assert } from 'chai';

// Sinon is a library used for mocking or verifying function calls in JavaScript.
import * as sinon from 'sinon';

// Require firebase-admin so we can stub out some of its methods.
import * as admin from 'firebase-admin';

// Require and initialize firebase-functions-test. Since we are not passing in any parameters, it will
// be initialized in an "offline mode", which means we have to stub out all the methods that interact
// with Firebase services.
import * as _test from 'firebase-functions-test';

const firebaseTest = _test();

describe('Cloud Functions', () => {
  let adminInitStub;

  // @ts-ignore
  before(() => {
    // [START stubAdminInit]
    // If index.js calls admin.initializeApp at the top of the file,
    // we need to stub it out before requiring index.js. This is because the
    // functions will be executed as a part of the require process.
    // Here we stub admin.initializeApp to be a dummy function that doesn't do anything.
    adminInitStub = sinon.stub(admin, 'initializeApp');
    // [END stubAdminInit]
  });

  // @ts-ignore
  after(() => {
    // Restore admin.initializeApp() to its original method.
    adminInitStub.restore();

    // Do other cleanup tasks.
    firebaseTest.cleanup();

    // Cleaning up env
    process.env.FUNCTION_NAME = undefined;
  });

  describe('signUp', () => {
    process.env.FUNCTION_NAME = 'signUp';

    it('it should write all the default data', async () => {

      const firebaseObject = {
        firestore: () => ({
          collection: () => ({
            doc: () => {}
          }),
          batch: () => ({
            set: () => {},
            commit: () => Promise.resolve('ok')
          })
        })
      };

      adminInitStub.callsFake(() => firebaseObject);

      const userSignup = require('../src/userSignup');
      const user = {
        id: 'testId'
      };

      const wrapped = firebaseTest.wrap(userSignup);

      assert.equal(await wrapped(user), 'ok');
    });

    it('it should NOT write all the default data', async () => {

      const firebaseObject = {
        firestore: () => ({
          collection: () => ({
            doc: () => {}
          }),
          batch: () => ({
            set: () => {},
            commit: () => Promise.reject('error')
          })
        })
      };

      adminInitStub.callsFake(() => firebaseObject);

      const userSignup = require('../src/userSignup');
      const user = {
        id: 'testId'
      };

      const wrapped = firebaseTest.wrap(userSignup);

      assert.equal(await wrapped(user), 'error');
    });
  });
});