createArticle.test.js

import expect from 'expect';
import request from 'supertest';
import app from '../app'; // the web server

const mockData = {
  "article": {
    "title": "",
    "description": "Ever wonder how?",
    "body": "You have to believe",
    "tagList": ["reactjs", "angularjs", "dragons"]
  }
}

describe('POST /api/articles create an article', () =>{
  it('should not create the article when title is empty', (done) => {
    request(app)
      .post('/api/articles')
      .send(mockdata)
      .expect(400)
      .expect(res => {
        expect(res.body).toHaveProperty('errors');
        expect(res.body.errors.body.length).toBe(1);
        expect(res.body.errors.body[0]).toBe('can\'t be empty');
    })
    .end(done);
  }
});

Good job on your TDD, great initiative on thinking about the possible scenarios.

Creating an article without a title will be impossible to generate a slug. Good job providing a test that ensures that the article should not be created if the title property is empty.

Great job on taking the initiative to add a test to check for title property before creating an article, this will ensure that an article does not get created with an incomplete data.

Great one. One little something though, imports come first :P.

Nice work!, Well laid out. Kudos.

Nice one! You checked for an empty title, I bet no user will be able to create an article without a title with this test, that's fine, keep it up.