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codeql-action/node_modules/eslint-plugin-escompat/README.md
2024-12-03 18:37:29 +00:00

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# eslint-plugin-escompat
This plugin will report eslint errors for code which - if left untranspiled -
will not work in some browsers.
This is useful if you intend to ship code without first using a transpiler, such
as [Babel](https://babeljs.io).
This _won't_ lint for features that can be polyfilled. For that you can use
[eslint-plugin-compat][epc].
## Installation
```bash
npm install --save-dev eslint-plugin-escompat
```
## Usage for Flat Configs (eslint.config.js) - ESLint >= 8
```js
// eslint.config.js
import globals from 'globals';
import escompat from 'eslint-plugin-escompat';
export default [
{
plugins: {
escompat
},
languageOptions: {
globals: globals.browser
},
rules: {
// Configure the individual `"escompat/*"` rules, e.g.:
'escompat/no-async-generator': ['error'],
'escompat/no-numeric-separators': ['error']
}
}
];
```
Alternatively, you can use the `recommended` configuration which will do the
plugins for you, with all recommended `"escompat/*"` rules reporting errors.
```js
import globals from 'globals';
import escompat from 'eslint-plugin-escompat';
export default [
{
languageOptions: {
globals: globals.browser
}
},
escompat.configs['flat/recommended']
];
```
## Usage for .eslintrc configs - ESLint < 9
Add `"escompat"` to `.eslintrc` `"plugins"` section, add `"browser": true` to
`"env"`, then configure the individual `"escompat/*"` rules.
Alternatively, you can use the `recommended` configuration which will do this
for you, with the `"escompat/*"` rules reporting errors (as in the snippet
above).
```js
// .eslintrc
{
"extends": ["plugin:escompat/recommended"]
}
```
### TypeScript Users
Aside from the `recommended` config, there are also multiple `typescript`
configs which can be used if you're using TypeScript. The TypeScript configs
only enable some of the rules, avoiding enabling rules for which `typescript`
safely transpiles down to a more compatible syntax. Extend the typescript config
that matches your `tsconfig.json` `target` value.
For flat configs:
```js
import globals from 'globals';
import escompat from 'eslint-plugin-escompat';
export default [
{
languageOptions: {
globals: globals.browser
}
},
// The TypeScript configs are in array form, so we need to
// spread them out here
...escompat.configs['flat/typescript-2016']
];
```
or for `.eslintrc`:
```js
{
"extends": ["plugin:escompat/typescript-2016"]
}
```
## Targeting Browsers
`eslint-plugin-escompat` uses the `browserslist` configuration in `package.json`
If you have a browserslist, it is safe to enable all of these rules - as any that
do not coincide with your chosen browsers will be turned off automatically.
See [browserslist/browserslist](https://github.com/browserslist/browserslist)
for configuration. Here's some examples:
```js
// Simple configuration (package.json)
{
// ...
"browserslist": ["last 1 versions", "not ie <= 8"],
}
```
```js
// Use development and production configurations (package.json)
{
// ...
"browserslist": {
"development": ["last 2 versions"],
"production": ["last 4 versions"]
}
}
```
:bulb: You can also define browsers in a
[separate browserslist file](https://github.com/browserslist/browserslist#config-file)
## Rules
- [no-async-generator](./docs/no-async-generator.md)
- [no-async-iteration](./docs/no-async-iteration.md)
- [no-bigint](./docs/no-bigint.md)
- [no-bind-operator](./docs/no-bind-operator.md)
- [no-class-static-blocks](./docs/no-class-static-blocks.md)
- [no-computed-public-class-fields](./docs/no-computed-public-class-fields.md)
- [no-do-expression](./docs/no-do-expression.md)
- [no-dynamic-imports](./docs/no-dynamic-imports.md)
- [no-edge-destructure-bug](./docs/no-edge-destructure-bug.md)
- [no-exponentiation-operator](./docs/no-exponentiation-operator.md)
- [no-hashbang-comment](./docs/no-hashbang-comment.md)
- [no-logical-assignment-operator](./docs/no-logical-assignment-operator.md)
- [no-nullish-coalescing](./docs/no-nullish-coalescing.md)
- [no-numeric-separators](./docs/no-numeric-separators.md)
- [no-object-rest-spread](./docs/no-object-rest-spread.md)
- [no-optional-catch](./docs/no-optional-catch.md)
- [no-optional-chaining](./docs/no-optional-chaining.md)
- [no-pipeline-operator](./docs/no-pipeline-operator.md)
- [no-private-class-fields](./docs/no-private-class-fields.md)
- [no-public-instance-class-fields](./docs/no-public-instance-class-fields.md)
- [no-public-static-class-fields](./docs/no-public-static-class-fields.md)
- [no-regexp-duplicate-named-groups](./docs/no-regexp-duplicate-named-groups.md)
- [no-regexp-lookbehind](./docs/no-regexp-lookbehind.md)
- [no-regexp-named-group](./docs/no-regexp-named-group.md)
- [no-regexp-s-flag](./docs/no-regexp-s-flag.md)
- [no-regexp-v-flag](./docs/no-regexp-v-flag.md)
- [no-top-level-await](./docs/no-top-level-await.md)
## Inspiration
This project was largely inspired by the great [eslint-plugin-compat][epc]
library.
[epc]: https://github.com/amilajack/eslint-plugin-compat