Chai: Add an ES6-friendly way to register "should"

[callumlocke]

I suggest adding a file named should.js at the root of this project that auto-registers 'should', i.e. require('./index').should();.

/* CURRENT SITUATION */

  // commonjs style looks nice
  require('chai').should();

  // but es6 isn't so nice
  import chai from 'chai';
  chai.should();

  // or you can do this, but it's still 2 lines
  import {should} from 'chai';
  should();

/* PROPOSAL */

  // single-line way to register 'should' in ES6
  import `chai/should`;

  // nb. other libraries use this convention too
  import 'babel-core/register';
  import 'coffee-script/register';

Note: people sometimes think side-effecting imports feel dirty, but it's arguably less dirty than a globally side-effecting function call like .should(). When you have a 'fromless' import that doesn't assign any variables, the syntax is explicitly intended for side-effects.

[keithamus]

Something I'd like to address in the roadmap (https://github.com/chaijs/chai/issues/457). Not sure what the right way to address this is though, as each has its downsides, especially when using plugins:

/* CURRENT SITUATION */

  // commonjs style looks nice
  require('chai').use(require('some-plugin')).should();

  // but es6 isn't so nice
  import chai from 'chai';
  import somePlugin from 'some-plugin';
  chai.use(somePlugin).should();

  // or you can do this, but it's still 2 lines
  import chai, {should} from 'chai';
  import somePlugin from 'some-plugin';
  chai.use(somePlugin);
  should();

/* PROPOSAL */

  // single-line way to register 'should' in ES6
  import chai from 'chai';
  import somePlugin from 'some-plugin';
  chai.use(somePlugin);
  import `chai/should`;

  // nb. other libraries use this convention too
  import 'babel-core/register';
  import 'coffee-script/register';

[keithamus]

I suppose keeping chai.should(), chai.expect, chai.assert would be fine, but adding import 'chai/should' would help for expressiveness for those who don't use plugins. So the trifecta becomes:

// Plugin-less
import { expect } from 'chai'
import { assert } from 'chai'
import 'chai/should'
// if you need should.exist/should.fail etc:
import should from 'chai/should'

// With plugins
import chai from 'chai';
import somePlugin from 'some-plugin';
const expect = chai.use(somePlugin).expect

import chai from 'chai';
import somePlugin from 'some-plugin';
const assert = chai.use(somePlugin).assert

import chai from 'chai';
import somePlugin from 'some-plugin';
const should = chai.use(somePlugin).should()

[keithamus]

@callumlocke how do you feel about making a PR for this? It should simply be a case of creating a file named should.js at the top level, which has these contents:

module.exports = require('./').should()

[jonaswindey]

I'm getting
Error: Cannot find module 'chai/should'

when using this syntax (chai 3.5.0)

[keithamus]

@jonaswindey this should be released as part of 4.0.0, which will be out soon 😄

[pyros2097]

Well the documentation seems to be updated to the latest syntax. Will need to wait for 4.0.0 release then.
http://chaijs.com/guide/styles/#should

[pyros2097]

After combing the pr's I found this and it worked.

import "chai/register-should"

Maybe the documentation needs to be updated later.