JavaScript Standard Style does not recognize Mocha

Question

I have a Mocha test file that looks like this:

var expect = require('chai').expect
var muting = require('../muting')

describe('muting', function () {
  describe('init()', function () {
    it('should inject an object into twitter', function () {
      var twitter = 'twitter'
      muting.init(twitter)
      expect(muting.twitter).to.equal(twitter)
    })
  })
})

When I run mocha from the CLI, it runs the test successfully.

When I run standard (the executable for JavaScript Standard Style) I get errors on Mocha's framework functions like so:

standard: Use JavaScript Standard Style (https://github.com/feross/standard)   
c:\..\test\index.js:5:0: 'describe' is not defined.  
c:\..\test\index.js:6:2: 'describe' is not defined.  
c:\..\test\index.js:7:4: 'it' is not defined.

What's the cleanest way to make Standard not complain about these functions?

score 213 · Answer 1 · answered May 01 '18 at 05:26

213

I prefer to edit my .eslintrc and add mocha to env section:

...
"env": {
  "commonjs": true,
  "node": true,
  "mocha": true
},
...

this way my package.json file is kept clean, also vscode plugin for eslint understands it better

answered May 01 '18 at 05:26

Developerium

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Yes, this should be the approved answer. – Wachaga Mwaura Jun 26 '19 at 12:17
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I also second the fact that this should be the approved answer. – Ezrqn Kemboi Mar 11 '20 at 06:55
Does `standard` track `.eslintrc`? – Alejandro Dec 15 '21 at 10:02

score 167 · Accepted Answer · edited Feb 07 '19 at 18:11

167

Actually, you don't need to list every single global variable in your package.json

You can specify environments instead like this:

"standard": {
  "env": [ "mocha" ]
}

Source: Official ESLint configuration docs.

edited Feb 07 '19 at 18:11

jbarros

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answered Jul 29 '16 at 21:01

Krzysztof Kaczor

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Good solution. Doesn't that mean I can call `it` in regular non-test code and it will pass linting? In other words. Can it be restricted only to test classes? – Ashley Dec 04 '16 at 17:44
3

Yeah, that's the problem... `package.json` settings are 'global' for linter. You can bypass it by providing different CLI arguments for different files: something like `standard --env mocha test/**/js` for lint-tests (not tested), but IRL i never had a need to tweak settings like this. – Krzysztof Kaczor Dec 04 '16 at 19:48
4

If using jest, you also can: "standard": { "env": [ "jest" ]} – palafox_e Jul 03 '18 at 22:30
To add to the comment by @palafox_e you can find out which values are available by navigating to: https://github.com/sindresorhus/globals/blob/master/globals.json – Wil Moore III Jul 09 '18 at 22:26
I'm using `jest` but I don't know why only works for mocha and not jest! – Developerium Jan 11 '20 at 06:30

Nick Tomlin · Answer 3 · 2016-01-07T17:57:25.967

66

while eslint's comment configuration works great for a single file, I prefer to use standard's package.json globals configuration to do this for my projects. E.g.

{
  "name": "my-package",
  "version": "1.0.0",
  "standard": {
    "globals": [
      "describe",
      "context",
      "before",
      "beforeEach",
      "after",
      "afterEach",
      "it",
      "expect"
    ]
  }
}

edited Jan 07 '16 at 17:57

answered Jan 07 '16 at 17:50

Nick Tomlin

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score 59 · Answer 4 · answered Nov 17 '16 at 10:23

59

for eslint use this line on the beginning of test_file.js

/* eslint-env mocha */

answered Nov 17 '16 at 10:23

Ryu_hayabusa

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I prefer this solution! – Michael Ozeryansky Nov 29 '18 at 10:31
6

That's not a solution if you have to add it for every test file – Peadar Jul 25 '19 at 08:38
@Peadar Creating multiple `.eslintrc.json` is also not really beautiful, just because you do not want to add one line to the test. On the other hand creating another `.eslintrc.json` makes sense if you need more than that config for mocha, for example an extra plugin or so. – Ini Feb 02 '21 at 18:39
This work for me! A simple solution. – Fernando Magrosoto Feb 28 '22 at 16:36

Niklas Ingholt · Answer 5 · 2015-05-20T20:53:45.617

41

You can use the same solution as for web workers

/* global describe it */
var expect = require('chai').expect
var muting = require('../muting')

describe('muting', function () {
  describe('init()', function () {
    it('should inject an object into twitter', function () {
     var twitter = 'twitter'
     muting.init(twitter)
     expect(muting.twitter).to.equal(twitter)
    })
  })
})

edited May 20 '15 at 20:53

answered May 20 '15 at 09:09

Niklas Ingholt

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score 2 · Answer 6 · edited May 23 '17 at 11:54

As pointed out by Nick Tomlin you just need to declare globals.

I use to put it in the command line, since I have different globals for tests as for sources or different parts of the project.

For tests we should use

standard --global describe --global it test/

elsewhere in my project I want to lint code that uses jQuery so I use

standard --global $ src/client/

Bonus tip

If you are using vim with Syntastic you maybe want to add to your .vimrc

let b:syntastic_checkers = ['standard']
let g:syntastic_javascript_standard_args = "--global $ --global it --global describe"

JavaScript Standard Style does not recognize Mocha

6 Answers6

Bonus tip

Linked