npm-gate

A hard fork of lint-staged to support complex pre-commit commands both per staged file and as a set

See the original project here

Why

The original lint-staged project is focused on enforcing linting in pre-commit hook, this project aim at adding gating capability right inside npm and supported through git pre-commit hooks. This script will run arbitrary npm and shell tasks with a list of staged files as an argument, filtered by a specified glob pattern.

Installation and setup

1. npm install --save-dev npm-gate husky
2. Install and setup your linters just like you would do normally. Add appropriate .eslintrc, .stylelintrc, etc.
3. Update your package.json like this:

{
  "scripts": {
    "precommit": "npm-gate"
  },
  "npm-gate": {
    "*.js": ["eslint --fix", "git add"]
  }
}

Now change a few files, git add some of them to your commit and try to git commit them.

See examples and configuration below.

I recommend using husky to manage git hooks but you can use any other tool.

NOTE:

If you're using commitizen and having following npm-script { commit: git-cz }, precommit hook will run twice before commitizen cli and after the commit. This buggy behaviour is introduced by husky.

To mitigate this rename your commit npm script to something non git hook namespace like, for example { cz: git-cz }

Configuration

Starting with v3.1 you can now use different ways of configuring it:

• npm-gate object in your package.json
• .npmgaterc file in JSON or YML format
• npm-gate.config.js file in JS format

See cosmiconfig for more details on what formats are supported.

npm-gate supports simple and advanced config formats.

Simple config format

Should be an object where each value is a command to run and its key is a glob pattern to use for this command. This package uses minimatch for glob patterns.

package.json example:

{
  "scripts": {
    "my-task": "your-command"
  },
  "npm-gate": {
    "*": "my-task"
  }
}

.npmgaterc example

{
  "*": "my-task"
}

This config will execute npm run my-task with the list of currently staged files passed as arguments.

So, considering you did git add file1.ext file2.ext, npm-gate will run the following command:

npm run my-task -- file1.ext file2.ext

Advanced config format

To set options and keep npm-gate extensible, advanced format can be used. This should hold linters object in linters property.

Options

• linters — Object — keys (String) are glob patterns, values (Array<String> | String) are commands to execute.
• gitDir — Sets the relative path to the .git root. Useful when your package.json is located in a subdirectory. See working from a subdirectory
• concurrent — true — runs linters for each glob pattern simultaneously. If you don’t want this, you can set concurrent: false
• chunkSize — Max allowed chunk size based on number of files for glob pattern. This is important on windows based systems to avoid command length limitations. See #147
• subTaskConcurrency — 2 — Controls concurrency for processing chunks generated for each linter.
• verbose — false — runs npm-gate in verbose mode. When true it will use https://github.com/SamVerschueren/listr-verbose-renderer.
• globOptions — { matchBase: true, dot: true } — minimatch options to customize how glob patterns match files.

Filtering files

It is possible to run linters for certain paths only by using minimatch patterns. The paths used for filtering via minimatch are relative to the directory that contains the .git directory. The paths passed to the linters are absolute to avoid confusion in case they're executed with a different working directory, as would be the case when using the gitDir option.

{
  // .js files anywhere in the project
  "*.js": "eslint",
  // .js files anywhere in the project
  "**/*.js": "eslint",
  // .js file in the src directory
  "src/*.js": "eslint",
  // .js file anywhere within and below the src directory
  "src/**/*.js": "eslint",
}

Trapping the file name

It can be useful to avoid pushing the committed list of file at then end of the npm script/command. Example: when using cucumberJS, you don't want the pre-commit to be treating all your committed javascript files as gherkin feature files. In that case, you can trap the files name list using a complex command, like this:

{
  "*.js": "npm run test",
  "codeaway/**/*.js": { "command": "cucumber-js testcodeaway/features", "trap": true}
}

It will now launch your npm script/command if any *.js files are committed in codeaway/ but without pushing the file list in the command

Pretty command name

You can also customize the displayed command name in the prompt, like this:

{
  "*.js": {"name": "my very important command", "command": "npm run test" }
}

Advanced commands (using a template)

For more advanced uses, a (light) templating system allows some flexibility regarding your command parsing. All 'patterns' have to be enclosed in the '<' and '>'. All enclosed expression will be repeated as many time as there is pre-commited files. Inside the enclosure, 4 patterns are available to delimit the pre-commited filename expansion :

• <> or <full> : to insert the full filename as given by git
• <filename> : to insert only the filename (without the extension)
• <path> : to insert the path of the file (beware, git will use a relative path to the root of the repo)
• <extension> : to insert the extension

Advanced command example

{
  // compress binary files anywhere in a subdirectory /bin where the file is currently
  "*.bin": "compress <--in=<full> --out=<path>/bin/<filename>.tar.gz>",
  // optimize all SVG file using svgo and pushing each optimized version with 'opt' before the extension
  "*.svg": "svgo --multipass <-i <> -o <path><filename>.opt.svg>",
  // translation of the simple "eslint" command in an advanced command (those are equivalent)
  "*.js": "eslint -- <<>>"
}

What commands are supported?

Supported are both local npm scripts (npm run-script), or any executables installed locally or globally via npm as well as any executable from your $PATH.

Using globally installed scripts is discouraged, since npm-gate may not work for someone who doesn’t have it installed.

npm-gate is using npm-which to locate locally installed scripts, so you don't need to add { "eslint": "eslint" } to the scripts section of your package.json. So in your .lintstagedrc you can write:

{
  "*.js": "eslint --fix"
}

Pass arguments to your commands separated by space as you would do in the shell. See examples below.

Starting from v2.0.0 sequences of commands are supported. Pass an array of commands instead of a single one and they will run sequentially. This is useful for running autoformatting tools like eslint --fix or stylefmt but can be used for any arbitrary sequences.

Reformatting the code

Tools like ESLint/TSLint or stylefmt can reformat your code according to an appropriate config by running eslint --fix/tslint --fix. After the code is reformatted, we want it to be added to the same commit. This can be done using following config:

{
  "*.js": ["eslint --fix", "git add"]
}

Working from a subdirectory

If your package.json is located in a subdirectory of the git root directory, you can use gitDir relative path to point there in order to make lint-staged work.

{
    "gitDir": "../",
    "linters":{
        "*": "my-task"
    }
}

Examples

All examples assuming you’ve already set up npm-gate and husky in the package.json.

{
  "name": "My project",
  "version": "0.1.0",
  "scripts": {
    "precommit": "npm-gate"
  },
  "npm-gate": {}
}

Note we don’t pass a path as an argument for the runners. This is important since npm-gate will do this for you. Please don’t reuse your tasks with paths from package.json.

ESLint with default parameters for *.js and *.jsx running as a pre-commit hook

{
  "*.{js,jsx}": "eslint"
}

Automatically fix code style with --fix and add to commit

{
  "*.js": ["eslint --fix", "git add"]
}

This will run eslint --fix and automatically add changes to the commit. Please note, that it doesn’t work well with committing hunks (git add -p).

Automatically fix code style with prettier for javascript + flow or typescript

{
  "*.{js,jsx}": ["prettier --parser flow --write", "git add"]
}

{
  "*.{ts,tsx}": ["prettier --parser typescript --write", "git add"]
}

Stylelint for CSS with defaults and for SCSS with SCSS syntax

{
  "*.css": "stylelint",
  "*.scss": "stylelint --syntax=scss"
}

Automatically fix SCSS style with stylefmt and add to commit

{
  "*.scss": ["stylefmt", "stylelint --syntax scss", "git add"]
}

Run PostCSS sorting, add files to commit and run Stylelint to check

{
  "*.scss": [
    "postcss --config path/to/your/config --replace",
    "stylelint",
    "git add"
  ]
}