index.js

const expect = require('expect');
const plugin = require('../index');
const createProbot = require('probot');

describe('plugin', () => {
  beforeEach(() => {
    config = {
        data: {
            content: Buffer.from('Thanks for making your first PR here!').toString('base64')
        }
    };
    //when probot run is called (probs will be changed in the near future)
    probot = createProbot({secret: 'test'});
    //mocks authentication
    github = {repos: {
                    getContent: expect.createSpy().andReturn(Promise.resolve(config))
                },
                issues: {
                    removeLabel: expect.createSpy()
                }};
    probot.robot.auth = () => Promise.resolve(github);

    probot.load(plugin);
    
    event = {
      payload: JSON.parse(JSON.stringify(require('./events/test_payload.json')))
    };
  });

  describe('first pull request', () => {
    it('gets content', async () => {
        //when web server recieves webhook
        //emit triggers event == robot.on
        probot.robot.webhook.emit('pull_request.opened', event);
        console.log(github.repos.getContent);
        expect(github.repos.getContent).toHaveBeenCalled();
    });
  });
});