Javascript: Getting an Error with "prefer-arrow-callback"

[framerate]

Error: /Users/framerate/code/project/server/node_modules/eslint-config-airbnb-base/rules/es6.js: Configuration for rule "prefer-arrow-callback" is invalid: Value "2,[object Object]" has more items than allowed.

Are you guys seeing this, as well?

[framerate]

Apparently there is a minor update to eslint that npm-check must not be catching. Upgrading made it go away.

[framerate]

Meh, it worked for a minute and now:

> ./node_modules/eslint/bin/eslint.js -c ./.eslintrc --ext .jsx --ext .js ./index.js ./lib/

Cannot read property 'value' of undefined
TypeError: Cannot read property 'value' of undefined
    at isEnclosedInParens (/Users/framerate/code/project/server/node_modules/eslint/lib/rules/no-return-assign.js:23:21)

Never had this bad luck with this package before! Just documenting here in case anyone else has the same issues.

[ljharb]

Are you running eslint.js directly, as opposed to the binary in node_modules/.bin?

[framerate]

@ljharb I run it like this:

./node_modules/eslint/bin/eslint.js -c ./.eslintrc --ext .jsx --ext .js ./index.js ./lib/

[framerate]

Apparently Eslint 2.10.0 has some major issues. See here

[ljharb]

@framerate you shouldn't. run it like ./node_modules/.bin/eslint --ext .jsx --ext .js ./index.js ./lib/, or better, in an npm run-script so you can use eslint without the node_modules path.

[framerate]

I use 'npm run lint' script. Is the .bin folder accessible or something that way?

[ljharb]

@framerate in that case, you should just be doing eslint --ext .jsx --ext .js ./index.js. You should basically never have to write node_modules anywhere.

[framerate]

Well, lean something new every day :). The local binary will overwrite if it's installed globally too?

[ljharb]

yep, npm run sets up the $PATH for you.

[framerate]

@ljharb thanks man. There's a bunch of little things like that I always felt weren't clear as I "grew up" with node/npm :)

[lucalanca]

This fixed it for me (I think, as I tried SO MANY THINGS!):

npm install [email protected] babel-eslint@6 --save-dev (as prescribed in https://github.com/babel/babel-eslint#install)

[poloka]

I tried the npm install that @lucalanca noted and I'm still receiving the error when running 'npm test'

╰─➤  npm test                                                                                                                                    1 ↵

> [email protected] test /Users/poloka/dev/orion_mpage_component
> launcher -t

/Users/poloka/dev/orion_mpage_component/node_modules/launcher/node_modules/eslint/lib/config/config-file.js:332
            throw e;
            ^

Error: /Users/poloka/dev/orion_mpage_component/node_modules/eslint-config-airbnb-base/rules/es6.js:
    Configuration for rule "prefer-arrow-callback" is invalid:
    Value "2,[object Object]" has more items than allowed.

Referenced from: airbnb-base
Referenced from: /Users/poloka/dev/orion_mpage_component/.eslintrc.json
    at validateRuleOptions (/Users/poloka/dev/orion_mpage_component/node_modules/launcher/node_modules/eslint/lib/config/config-validator.js:102:15)
    at /Users/poloka/dev/orion_mpage_component/node_modules/launcher/node_modules/eslint/lib/config/config-validator.js:148:13
    at Array.forEach (native)
    at Object.validate (/Users/poloka/dev/orion_mpage_component/node_modules/launcher/node_modules/eslint/lib/config/config-validator.js:147:35)

My dev dependencies are noted as:

  "devDependencies": {
    "babel-core": "^6.4.0",
    "babel-eslint": "^6.0.4",
    "babel-loader": "^6.2.1",
    "babel-preset-es2015": "^6.3.13",
    "commander": "^2.9.0",
    "csslint": "^0.10.0",
    "eslint": "^2.11.1",
    "eslint-config-airbnb": "^9.0.1",
    "eslint-config-airbnb-base": "^3.0.1",
    "eslint-plugin-import": "^1.8.1",
    "eslint-plugin-jsx-a11y": "^1.3.0",
    "eslint-plugin-react": "^5.1.1",
    "jshint": "^2.9.1",
    "less": "^2.6.1",
    "less-loader": "^2.2.3",
    "less-plugin-clean-css": "^1.5.1",
    "matchdep": "^1.0.0",
    "prettyjson": "^1.1.3",
    "uglify-js": "^2.6.2",
    "webpack": "^1.13.0",
    "webpack-dev-server": "^1.14.1"
  }

[ljharb]

What is launcher? Any chance it's running a global eslint binary? If you do npm uninstall -g eslint, and then run the tests, what happens?

[poloka]

launcher is an internally written unit testing framework. I've actually realized that the dependency its pulling for eslint is 1.10.3

├── [email protected]
└─┬ [email protected]
  └── [email protected]

So looks like my problem.

[rex]

So my takeaway from this thread is that ESLint-ing in Sublime Text is broken unless I'm using ESLint>=2.x? Because if so that is bonkers and a huge disappointment. I'm getting the same errors as @poloka above.

Error: /usr/local/lib/node_modules/eslint-config-airbnb/node_modules/eslint-config-airbnb-base/rules/es6.js:
  Configuration for rule "prefer-arrow-callback" is invalid:
  Value "2,[object Object]" has more items than allowed.

Referenced from: /usr/local/lib/node_modules/eslint-config-airbnb/node_modules/eslint-config-airbnb-base/index.js
Referenced from: airbnb/base
Referenced from: topgolf
Referenced from: /Users/PierceMoore/Code/lager/.eslintrc
    at validateRuleOptions (/usr/local/lib/node_modules/eslint/lib/config/config-validator.js:102:15)
    at /usr/local/lib/node_modules/eslint/lib/config/config-validator.js:148:13
    at Array.forEach (native)
    at Object.validate (/usr/local/lib/node_modules/eslint/lib/config/config-validator.js:147:35)
    at load (/usr/local/lib/node_modules/eslint/lib/config/config-file.js:390:19)
    at /usr/local/lib/node_modules/eslint/lib/config/config-file.js:326:36
    at Array.reduceRight (native)
    at applyExtends (/usr/local/lib/node_modules/eslint/lib/config/config-file.js:309:28)
    at load (/usr/local/lib/node_modules/eslint/lib/config/config-file.js:395:22)
    at /usr/local/lib/node_modules/eslint/lib/config/config-file.js:326:36

λ which eslint
/usr/local/bin/eslint

λ eslint -v
v1.10.3

[ljharb]

@rex no, but you shouldn't be running the global eslint. run your local one. Also, eslint v1 is ancient, and the latest version of this config requires eslint v3.

[rex]

@ljharb Yeah... You're right. I just looked at how long it's been, my team and I are way behind in terms of ESLint version. 1.x really _is_ that far behind. I will hopefully be able to use this as a stimulus in the direction of upgrading. We rely extremely heavily on the work that you Airbnb guys do on this config, like so many others, and I appreciate it :)