Add `reactLibrary` setting

[cherryblossom000]

Add a reactLibrary setting for the name of the React library (defaults to 'react'). This would be helpful for Preact users.

Currently, the jsx-fragments rule (set to syntax) doesn't warn about this:

import {Fragment} from 'preact'

const foo = <Fragment>foo</Fragment>

Checking for the configured reactLibrary setting instead of the hard-coded 'react' would make this rule (and possibly others, I haven't really looked into this plugin that much) more flexible.

[ljharb]

This already exists: https://github.com/yannickcr/eslint-plugin-react#configuration see “pragma”

[cherryblossom000]

@ljharb That only works for detecting <Preact.Fragment> and not Fragment if it was imported from 'preact'.

As you can see here, for imports the rule only checks if the imported module is 'react':

https://github.com/yannickcr/eslint-plugin-react/blob/0e9a193435454cd4891760d2bc5efdb2d2bc6294/lib/rules/jsx-fragments.js#L115-L124

https://github.com/yannickcr/eslint-plugin-react/blob/0e9a193435454cd4891760d2bc5efdb2d2bc6294/lib/rules/jsx-fragments.js#L155-L165

Here's a minimal example of my issue:

.eslintrc.yml

root: true
plugins: [react]
parserOptions:
  ecmaFeatures:
    jsx: true
  ecmaVersion: 6
  sourceType: module
settings:
  react:
    pragma: Preact # this doesn't do anything except report on Preact.Fragment
rules:
  react/jsx-fragments: 2 # mode defaults to syntax

test.jsx

import {Fragment} from 'preact'

const foo = <Fragment>foo</Fragment>

Running npx eslint test.jsx does not report any linting errors.

eslint version: 7.18.0
eslint-plugin-react version: 7.22.0

[ljharb]

In that case, the rule definitely shouldn’t be hardcoded - i understand what you mean now.

A PR to add this setting would be appreciated.