ESLint Plugin TypeScript
An ESLint plugin which provides lint rules for TypeScript codebases.
## Getting Started
- **[You can find our Getting Started docs here](https://typescript-eslint.io/docs)**
- **[You can find our FAQ / Troubleshooting docs here](https://typescript-eslint.io/docs/linting/troubleshooting)**
These docs walk you through setting up ESLint, this plugin, and our parser. If you know what you're doing and just want to quick start, read on...
## Quick-start
### Installation
Make sure you have TypeScript and [`@typescript-eslint/parser`](../parser) installed:
```bash
$ yarn add -D typescript @typescript-eslint/parser
$ npm i --save-dev typescript @typescript-eslint/parser
```
Then install the plugin:
```bash
$ yarn add -D @typescript-eslint/eslint-plugin
$ npm i --save-dev @typescript-eslint/eslint-plugin
```
It is important that you use the same version number for `@typescript-eslint/parser` and `@typescript-eslint/eslint-plugin`.
**Note:** If you installed ESLint globally (using the `-g` flag) then you must also install `@typescript-eslint/eslint-plugin` globally.
### Usage
Add `@typescript-eslint/parser` to the `parser` field and `@typescript-eslint` to the plugins section of your `.eslintrc` configuration file, then configure the rules you want to use under the rules section.
```json
{
"parser": "@typescript-eslint/parser",
"plugins": ["@typescript-eslint"],
"rules": {
"@typescript-eslint/rule-name": "error"
}
}
```
You can also enable all the recommended rules for our plugin. Add `plugin:@typescript-eslint/recommended` in extends:
```json
{
"extends": ["plugin:@typescript-eslint/recommended"]
}
```
### Recommended Configs
You can also use [`eslint:recommended`](https://eslint.org/docs/rules/) (the set of rules which are recommended for all projects by the ESLint Team) with this plugin:
```json
{
"extends": ["eslint:recommended", "plugin:@typescript-eslint/recommended"]
}
```
As of version 2 of this plugin, _by design_, none of the rules in the main `recommended` config require type-checking in order to run. This means that they are more lightweight and faster to run.
Some highly valuable rules require type-checking in order to be implemented correctly, however, so we provide an additional config you can extend from called `recommended-requiring-type-checking`. You would apply this _in addition_ to the recommended configs previously mentioned, e.g.:
```json
{
"extends": [
"eslint:recommended",
"plugin:@typescript-eslint/recommended",
"plugin:@typescript-eslint/recommended-requiring-type-checking"
]
}
```
Pro Tip: For larger codebases you may want to consider splitting our linting into two separate stages: 1. fast feedback rules which operate purely based on syntax (no type-checking), 2. rules which are based on semantics (type-checking).
**[You can read more about linting with type information here](https://typescript-eslint.io/docs/linting/typed-linting)**
## Supported Rules
For the exhaustive list of supported rules, [please see our website](https://typescript-eslint.io/rules/).
## Contributing
[See the contributing guide here](../../CONTRIBUTING.md).