Linting issue with neutrino v9

[helfi92]

• What version of Neutrino are you using?
  v9
• Are you using the Yarn client or the npm client? What version?
  yarn, v1.10.1
• What version of Node.js are you using?
  v8.10
• What operating system are you using?
  macOS High Sierra
• What did you do?
  Attempt to migrate to neutrino v9
• What did you expect to happen?
  yarn start shows the same linting errors as yarn lint
• What actually happened, contrary to your expectations?
  yarn start shows linting errors but yarn lint shows no errors.

Running yarn start or yarn lint with console.log(JSON.stringify(neutrino.config.toConfig(), null, 2)); in .neutrinorc.js shows the eslint baseConfig extends property set as:

  extends: [
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb/index.js",
    "eslint-config-prettier",
    "plugin:react/recommended"
  ],

However, when running eslint --print-config ., the extends field is set as:

  "extends": [
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/rules/best-practices.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/rules/errors.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/rules/node.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/rules/style.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/rules/variables.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/rules/es6.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/rules/imports.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/index.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb-base/rules/strict.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb/rules/react.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb/rules/react-a11y.js",
    "/Users/haali/Documents/Mozilla/projects/taskcluster-web/node_modules/eslint-config-airbnb/index.js",
    "eslint-config-prettier",
    "plugin:react/recommended"
  ]

I wonder if there's a merging issue somewhere. Here's the branch where I'm doing the migration: taskcluster/taskcluster-web#157

[edmorley]

Hi! Yeah it's possible there is a bug.

However it's worth noting that:

• eslint --print-config resolves the configuration, so I think it's expected that the contents of extends appears to be different, due to:
  https://github.com/airbnb/javascript/blob/24da5bb540de12117bcdfa7b6d8ce3c0ff4b6504/packages/eslint-config-airbnb/index.js#L2-L7
  ...ie: the issue might be being caused by something else.
• yarn lint defaults NODE_ENV to production, whereas yarn start defaults it to development, so for things like no-console (which I see is conditional on NODE_ENV), there will be differences (though not applicable in this case given "start" is seeming to be more strict).

What would be useful would be to have the full output of

• yarn neutrino --inspect --mode production (just the eslint section)
• node -p "require('./.eslintrc.js')"
• a sampling of the errors reported in yarn start but not by yarn lint

[helfi92]

yarn neutrino --inspect --mode production: https://gist.github.com/helfi92/e8e12dd92f12a24ea168056d7ff0fb66
node -p "require('./.eslintrc.js')": https://gist.github.com/helfi92/620ef914c5d3adc976021765477007d1

[helfi92]

The env field is structured a bit differently. Is this expected?

• https://gist.github.com/helfi92/e8e12dd92f12a24ea168056d7ff0fb66#file-tc-web-neutrino-production-L34-L41
• https://gist.github.com/helfi92/620ef914c5d3adc976021765477007d1#file-node-p-eslintrc-L48-L54

[helfi92]

A sample of errors reported in yarn start: https://gist.github.com/helfi92/d40f2da45f34ad4d8b85195fe211fe6c.

[edmorley]

I'll take a look soon, just deep in a few other bits at the moment.

The env field is structured a bit differently. Is this expected?

Yeah the schema for .eslintrc.js config is different from that accepted by ESLint's API (which is what eslint-loader has to use). See:
https://github.com/eslint/eslint/blob/master/conf/config-schema.js
https://eslint.org/docs/developer-guide/nodejs-api#cliengine

[edmorley]

A sample of errors reported in yarn start: https://gist.github.com/helfi92/d40f2da45f34ad4d8b85195fe211fe6c.

All of those errors are in .jsx files.

The PR's lint command uses:

$ yarn lint
yarn run v1.12.0
$ eslint --cache --format codeframe --ext mjs,js src test
...

ie: --ext mjs,js needs to be --ext mjs,jsx,js.

See:
https://master.neutrinojs.org/migration-guide/#neutrino-v8-to-v9

• neutrino lint can typically be replaced with eslint --cache --format codeframe --ext mjs,jsx,js src.