Getting Started with ESLint

ESLint is a tool for identifying and reporting on patterns found in ECMAScript/JavaScript code, with the goal of making code more consistent and avoiding bugs. In many ways, it is similar to JSLint and JSHint with a few exceptions:

ESLint 是在 ECMAScript/JavaScript 代码中识别和报告模式匹配的工具，它的目标是保证代码的一致性和避免错误。在许多方面，它和 JSLint、JSHint 相似，除了少数的例外：

Getting Started Tutorial

Why ESLint @0:00, Installing and using ESLint @2:20. Full ESLint Course at Pluralsight

Why ESLint @0:00, Installing and using ESLint @2:20. 去 Pluralsight 查看全部 ESLint 课程

Note that, for some reason, not everyone can see the vedio on youtube, so the translator use a vedio screenshot here instead of a vedio.

注：由于某些未知原因，你可能看不到 youtube 的视频，所以只放了视频截图。

Installation and Usage

Prerequisites: Node.js (>=6.14), npm version 3+.

先决条件：Node.js (>=6.14), npm version 3+。

You can install ESLint using npm:

你可以使用 npm 安装 ESLint：

$ npm install eslint --save-dev

You should then set up a configuration file:

紧接着你应该设置一个配置文件：

$ ./node_modules/.bin/eslint --init

After that, you can run ESLint on any file or directory like this:

之后，你可以在任何文件或目录上运行ESLint如下：

$ ./node_modules/.bin/eslint yourfile.js

It is also possible to install ESLint globally rather than locally (using npm install eslint --global). However, any plugins or shareable configs that you use must be installed locally in either case.

也可以在全局而不是本地安装 ESLint (使用 npm install eslint --global)。但是，你使用的任何插件或可共享配置都必须安装在本地。

Configuration

Note: If you are coming from a version before 1.0.0 please see the migration guide.

注意：如果你之前使用的版本低于 1.0.0，请查看 迁移指南。

After running eslint --init, you’ll have a .eslintrc file in your directory. In it, you’ll see some rules configured like this:

运行 eslint --init 之后，.eslintrc 文件会在你的文件夹中自动创建。你可以在 .eslintrc 文件中看到许多像这样的规则：

{
    "rules": {
        "semi": ["error", "always"],
        "quotes": ["error", "double"]
    }
}

The names "semi" and "quotes" are the names of rules in ESLint. The first value is the error level of the rule and can be one of these values:

"semi" 和 "quotes" 是 ESLint 中 规则 的名称。第一个值是错误级别，可以使下面的值之一：

The three error levels allow you fine-grained control over how ESLint applies rules (for more configuration options and details, see the configuration docs).

这三个错误级别可以允许你细粒度的控制 ESLint 是如何应用规则（更多关于配置选项和细节的问题，请查看配置文件）

Your .eslintrc configuration file will also include the line:

你的 .eslintrc 配置文件可以包含下面的一行：

    "extends": "eslint:recommended"

Because of this line, all of the rules marked “” on the rules page will be turned on. Alternatively, you can use configurations that others have created by searching for “eslint-config” on npmjs.com. ESLint will not lint your code unless you extend from a shared configuration or explicitly turn rules on in your configuration.

由于这行，所有在 规则页面 被标记为 “” 的规则将会默认开启。另外，你可以在 npmjs.com 搜索 “eslint-config” 使用别人创建好的配置。只有在你的配置文件中扩展了一个可分享的配置或者明确开启一个规则，ESLint 才会去校验你的代码。

Next Steps