tsc-watch/test/tsc-watch.it.js

The TypeScript compiler with onSuccess command

const { expect } = require('chai');
const sinon = require('sinon');
const mochaEventually = require('mocha-eventually');
const { driver } = require('./driver');

const eventually = fn => mochaEventually(fn, 8000, 10);

describe('TSC-Watch child process messages', () => {
  beforeEach(() => (this.listener = sinon.stub()));
  afterEach(() => driver.reset());

  it('Should send "first_success" on first success', () => {
    driver
      .subscribe('first_success', this.listener)
      .startWatch()
      .modifyAndSucceedAfter(1000);

    return eventually(() => expect(this.listener.callCount).to.be.equal(1));
  });

  it('Should send "success" on subsequent successes', () => {
    driver
      .subscribe('success', this.listener)
      .startWatch()
      .modifyAndSucceedAfter(1000);

    return eventually(() => expect(this.listener.callCount).to.be.equal(2));
  });

  it('Should send "compile_errors" when tsc compile errors occur', () => {
    driver
      .subscribe('compile_errors', this.listener)
      .startWatch({ failFirst: true })
      .modifyAndFailAfter(1500);

    return eventually(() => expect(this.listener.callCount).to.be.equal(2));
  });

  it('Should send "compile_errors" when pretty param was set', () => {
    driver.subscribe('compile_errors', this.listener).startWatch({ failFirst: true, pretty: true });

    return eventually(() => expect(this.listener.callCount).to.be.equal(1));
  });
});