JavaScript happiness style ❤️ XOXO
Enforce strict code style. Never discuss code style on a pull request again!
No decision-making. No .eslintrc
, .jshintrc
, .jscsrc
to manage. It just works!
Uses ESLint underneath.
- Tab indentation
- Semicolons
- Single-quotes
- No unused variables
- Space after keyword
if (condition) {}
- Always
===
instead of==
Any of these can be overridden if necessary.
Check out an example and the ESLint rules.
$ npm install --global xo
$ xo --help
Usage
$ xo [<file|glob> ...]
Options
--init Add XO to your project
--compact Compact output
--stdin Validate code from stdin
--esnext Enable ES2015 support and rules
--env Environment preset [Can be set multiple times]
--global Global variable [Can be set multiple times]
--ignore Additional paths to ignore [Can be set multiple times]
--space Use space indent instead of tabs [Default: 2]
Examples
$ xo
$ xo index.js
$ xo *.js !foo.js
$ xo --esnext --space
$ xo --esnext --env=node --env=mocha
Tips
Put options in package.json instead of using flags so other tools can read it.
The recommended workflow is to add XO locally to your project and run it with the tests.
Simply run $ xo --init
to add XO to your package.json
:
{
"name": "my-awesome-project",
"scripts": {
"test": "mocha"
},
"devDependencies": {
"mocha": "^2.0.0"
}
}
{
"name": "my-awesome-project",
"scripts": {
"test": "xo && mocha"
},
"devDependencies": {
"mocha": "^2.0.0",
"xo": "^0.5.0"
}
}
You can configure some options in XO by putting it in package.json
:
{
"name": "my-awesome-project",
"xo": {
"envs": ["node", "mocha"]
}
}
Globals and rules can be configured inline in files.
Type: boolean
Default: false
Enable ES2015 support and linting rules.
Type: array
Default: ['node']
Which environments your code is designed to run in. Each environment brings with it a certain set of predefined global variables.
Type: array
Additional global variables your code accesses during execution.
Type: array
Some paths are ignored by default. Additional ignores can be added here.
Type: boolean
, number
Default: false
(tab indentation)
Set it to true
to get 2-space indentation or specify the number of spaces.
This option exists for pragmatic reasons, but I would strongly recommend you read "Why tabs are superior".
Type: object
Override any of the default rules. See the ESLint docs for more info on each rule.
Please take a moment to consider if you really need to use this option.
The Standard style is a really cool idea. I too wish we could have one style to rule them all! Unfortunately, they made the mistake of pushing their own style instead of the most popular one. I don't think it's realistic to convert everyone. In contrast, XO is more pragmatic and has no aspiration of being the style. XO does use tabs by default, but everything is configurable if necessary.
XO is based on ESLint. This project started out as just a shareable ESLint config, but it quickly grew out of that. I wanted something even simpler. Just typing xo
and be done. No decision-making. No config. I also have some exciting future plans for it. However, you can still get most of the XO benefits while using ESLint directly with the ESLint shareable config.
- Sublime Text: SublimeLinter-contrib-xo
- Atom: atom-linter-xo
- eslint-config-xo - ESLint shareable config for XO
- eslint-config-xo-space - ESLint shareable config for XO with 2-space indent
- eslint-config-xo-react - ESLint shareable config for React to be used with the above
MIT © Sindre Sorhus