Need help getting the getter syntax to work in mocha

[dkniffin]

Hey. I really like the idea of this library, and have been wanting something like it for a while. Unfortunately, I can't quite seem to get it working in the way I want.

I'd like to use the get. syntax with mocha. I'm using the -u bdd-lazy-var flag when running mocha. Is that the right way to do that? In the docs, I see different usage here, but I'm not sure where I'd put that in my app, since I'm not currently doing new Mocha() anywhere.

[stalniy]

Hi,

If you want to use getter syntax you need to include it like this:

mocha -u bdd-lazy-var/getter

[dkniffin]

With that, I can get get('varname') to work, but not get.varname

[stalniy]

That's really strange!

Could you please share your setup?

This is what I did:

// index.spec.js
const { expect } = require('chai')

describe('test', () => {
  def('value', () => 5)

  it('works', () => {
    expect(get.value).to.equal(5)
  })
})

and then

$ npm test

> test@1.0.0 test /home/sergii/projects/test
> mocha -u bdd-lazy-var/getter index.spec.js



  test
    ✓ works


  1 passing (6ms)

[dkniffin]

The configs for the app I'm trying to install this into is pretty complex, but let me see if I can boil it down to the basic parts:

• I'm running yarn test, which maps to NODE_ENV=test mocha -u bdd-lazy-var/getter --require babel-core/register --opts 'support/mocha.opts' 'src/**/*.spec.*'
• support/mocha.opts has the following:

--require support/addons.js
--require support/loaders.js
--require support/globals.js

• support/addons.js has the following:

const chai = require('chai');
const chaiAsPromised = require('chai-as-promised');
const chaiImmutable = require('chai-immutable');
const chaiSorted = require('chai-sorted');
const Enzyme = require('enzyme');
const Adapter = require('enzyme-adapter-react-16');

chai.use(chaiAsPromised);
chai.use(chaiImmutable);
chai.use(chaiSorted);

Enzyme.configure({ adapter: new Adapter() });

• support/loaders.js has the following:

const nullExtensions = ['.css', '.scss', '.sass', '.png', '.jpg', '.svg'];

nullExtensions.forEach(function(extension) {
  require.extensions[extension] = function() {};
});

• support/globals.js has the following:

const chai = require('chai');
const faker = require('faker');
const enzyme = require('enzyme');
const sinon = require('sinon');
const fixtureFactory = require('./fixtures/factories');

global.expect = chai.expect;
global.faker = faker;
global.fixture = fixtureFactory;
global.sandbox = sinon.sandbox;
global.shallow = enzyme.shallow;
global.window = {
  location: {
    hostname: 'localhost'
  }
};
// NOTE: get and def come from the bdd-lazy-var library

Then, with a slightly modified version of your test above:

describe.only('test', () => {
  def('value', () => 5);

  it('works', () => {
    expect(get.value).to.equal(5);
  });
});

I get

> yt
yarn run v1.3.2
$ NODE_ENV=test mocha -u bdd-lazy-var/getter --require babel-core/register --opts 'support/mocha.opts' 'src/**/*.spec.*'


  test
    1) works


  0 passing (468ms)
  1 failing

  1) test
       works:
     AssertionError: expected undefined to equal 5
      at Context.<anonymous> (src/test.spec.js:5:26)



error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

[stalniy]

Created a repository to test things :) https://github.com/stalniy/bdd-lazy-var-test . Currently it works. Will try to add babel/register and loaders

[dkniffin]

@stalniy Awesome, thanks! Let me know how it goes

[dkniffin]

@stalniy I'm still investigating on my end, and I realized if I only run that one test, it works fine. Something else is messing with it.

[stalniy]

maybe you already use some get variable and it overrides provided by bdd-lazy-var ?

[stalniy]

added everything except of ./fixtures/factories and tests still works

[dkniffin]

Alright, I'm very confused now. I went through and commented out all of my other spec files, but it's still failing:

> yt
yarn run v1.3.2
$ NODE_ENV=test mocha -u bdd-lazy-var/getter --require babel-core/register --opts 'support/mocha.opts' 'src/**/*.spec.js'


  test
    1) works


  0 passing (41ms)
  1 failing

  1) test
       works:
     AssertionError: expected undefined to equal 5
      at Context.<anonymous> (src/test.spec.js:5:26)



error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Then if I just change it to run that single file (src/**/*.spec.js vs src/test.spec.js) it works:

> yt
yarn run v1.3.2
$ NODE_ENV=test mocha -u bdd-lazy-var/getter --require babel-core/register --opts 'support/mocha.opts' 'src/test.spec.js'


  test
    ✓ works


  1 passing (49ms)

✨  Done in 1.77s.

[stalniy]

try to do this in your test:

describe.only('test', () => {
  def('value', () => 5);

  it('works', () => {
    console.log(get)
    console.log('value' in get)

    expect(get.value).to.equal(5);
  });
});

[dkniffin]

Failing version:

> yt
yarn run v1.3.2
$ NODE_ENV=test mocha -u bdd-lazy-var/getter --require babel-core/register --opts 'support/mocha.opts' 'src/**/*.spec.js'


  test
{ [Function: get$$1] variable: [Function], definitionOf: [Function] }
false
    1) works


  0 passing (49ms)
  1 failing

  1) test
       works:
     AssertionError: expected undefined to equal 5
      at Context.<anonymous> (src/test.spec.js:8:26)



error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Working version:

> yt
yarn run v1.3.2
$ NODE_ENV=test mocha -u bdd-lazy-var/getter --require babel-core/register --opts 'support/mocha.opts' 'src/test.spec.js'


  test
{ [Function: get$$1]
  variable: [Function],
  definitionOf: [Function],
  [Symbol(__lazyVars)]: { value: true } }
true
    ✓ works


  1 passing (51ms)

✨  Done in 2.65s.

[stalniy]

ok, so the good news is that it uses the correct get function :) Now lets check whether in some other places you use require('bdd-lazy-var') (without /getter). Potentially it may override bdd-lazy-var/getter

[dkniffin]

Nope, a quick search doesn't show any other instances of bdd-lazy-var, other than the -u, and the package.json version and yarn.lock

[dkniffin]

Also, just as a sanity check, I made sure this spec is the only one with content:

> cat src/**/*.spec.js | grep -v '//' | grep -Ev "^$"
describe('test', function() {
  def('value', function() {
    return 5;
  });
  it('works', function() {
    console.log(get);
    expect(get.value).to.equal(5);
  });
});

[dkniffin]

Where does that functionality get set up in the library? I see get here: https://github.com/stalniy/bdd-lazy-var/blob/master/lib/interface.js#L6, but how do you manage putting the properties onto get.?

[stalniy]

I see.
Another idea. Let's try to use 2 files with tests in that example repo. Maybe the issue is that the lib redefines itself if used for 2 files

[stalniy]

I'm currently a bit busy. Can't test. But will try to look into it in few hours at home

[dkniffin]

Awesome. Thanks for your help on this! No rush

[stalniy]

I set properties on get inside lib/interface/dialects/bdd_*_getter.js

There is a hook function, onDefine which is called each time def is called

[stalniy]

This is a bug. Looks like nobody except of you tried to use getter dialect ;) Some time I used get('varName') and then switched to $varName.

Going to fix this soon!

[stalniy]

the issue appears when you have 2 separate files with tests. Mocha defines ui interface for each tests file. My tests were not able to catch this error because I have only 1 file for tests :)

I was able to reproduce this issue in that example repo

[dkniffin]

Nice! Glad I could be helpful. 😄

[stalniy]

Published 2.2.2 version. Now everything should work as expected

Thanks for the issue 👍