Correct custom eslint instructions

[KyleAMathews]

If people customize their eslint setup, we should recommend they start from our default setup https://www.npmjs.com/package/eslint-config-react-app and go from there.

Our current docs recommend something entirely different:
https://www.gatsbyjs.org/docs/eslint/#configuring-eslint

[KyleAMathews]

This is the file that defines our setup https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby/src/utils/eslint-config.js

[KyleAMathews]

@kkemple looked into writing out the schema so then a custom eslint config could use it. @freiksenet @stefanprobst — it'd be great to do that #6167

[stefanprobst]

@KyleAMathews this is on the roadmap. In the meantime there is this plugin.

[KyleAMathews]

Ok, no worries @stefanprobst

So for now we should just recommend people use:

{
      globals: {
        graphql: true,
        __PATH_PREFIX__: true,
      },
      extends: `react-app`,
}

[DSchau]

Would love for someone to pick this up--right now we're displaying a document that is a little bit less focused than we'd like.

Description

• Update this document with the above instructions per @KyleAMathews
  • Why?
    • This document is doing a bit too many things, e.g. adding prettier
    • We should advocate simple set ups that work out of the box and scale as needed
• (Longer term!) we should expose something like gatsby-config-eslint which will be an opinionated set of defaults that are currently internalized here
  • This requires changes to dumping our schema, so a quicker win is to first update the documentation and longer term externalize our config so it can be used by anyone

[lukebrobbs]

Hi, sorry to sound dumb, but I'd like to dive into a bit of open source, and this seems like a good place to start. Is this replacing the current .eslintrc.js example with the config written by @KyleAMathews above? Thanks

[DSchau]

@lukebrobbs not a dumb question, at all!

Yep, exactly. You'll want to edit this file and instructions to be a little simpler, and just install the necessary dependencies, e.g. eslint-config-react-app

Feel free to reach out if we can help with anything else!

[lukebrobbs]

Great, thanks! The npm page for eslint-config-react-app recommends installing the following for projects not build with Create React App:

npm install --save-dev eslint-config-react-app babel-eslint@9.x eslint@5.x eslint-plugin-flowtype@2.x eslint-plugin-import@2.x eslint-plugin-jsx-a11y@6.x eslint-plugin-react@7.x

Will all of this need to be installed with Gatsby?