old_contents: /* eslint-env mocha */
  const User = require('../../../data/models/user');
  const expect = require('chai').expect;
  
  before(() =>
    User.query().del().then(() =>
      User.register('user0@example.com', '123456')));
  
  describe('User#register', () => {
    it('register with an unused email', () => User.register('user1@example.com', '12345')
        .then((user) => {
          expect(user.toJSON().email).to.equal('user1@example.com');
        }));
  
    it('register with a taken email', (done) => {
      User.register('user0@example.com', '12345')
        .then(() => {
          done(new Error('broken UNIQUE constraint'));
        })
        .catch(() => {
          done();
        });
    });
  });
  
  describe('User#find', () => {
    it('fetch with email', (done) => {
      User.find('user0@example.com')
        .then((user) => {
          done(user ? null : new Error('no user model found'));
        })
        .catch((err) => {
          done(err);
        });
    });
  });
  
  
new_contents: /* eslint-env mocha */
  const User = require('../../../data/models/user');
  const expect = require('chai').expect;
  
  before(() =>
    User.query().del().then(() =>
      User.register('user0@example.com', '123456')));
  
  describe('User#register', () => {
    it('register with an unused email', () => User.register('user1@example.com', '12345')
        .then((user) => {
          expect(user.toJSON().email).to.equal('user1@example.com');
        }));
  
    it('register with a taken email', (done) => {
      User.register('user0@example.com', '12345')
        .then(() => {
          done(new Error('broken UNIQUE constraint'));
        })
        .catch(() => {
          done();
        });
    });
  });
  
  describe('User#find', () => {
    it('fetch with email', (done) => {
      User.find('user11@example.com')
        .then((user) => {
          done(user ? null : new Error('no user model found'));
        })
        .catch((err) => {
          done(err);
        });
    });
  });
  
  
subject: make tests fail