precommit-hook

A useful pre-commit hook for git based projects that lints and runs npm test

This module is a handy little tool that I wrote to help enforce code quality in Node.js projects. It allows you to run any scripts defined in your package.json before a commit is made.

No one likes a messy code base. When working on a team, it becomes more and more difficult to make sure that your project's code stays consistent and error free. Since the hook can lint all of the project's code, based on your configuration, you can be sure that at the very least standards are being followed. It can also run build steps, unit tests, or any other script you like.

Having a tool that automates this process has been priceless for us, and has very much improved the quality of our code.

When you install this project, by default it will create sane .jshintignore and .jshintrc files for you if they do not already exist. That means it's safe to upgrade the hook after customizing these files, as they will never be overwritten. If you have your jshint configuration in your package.json, then the .jshintrc file will not be created ever.

You can prevent this behavior by modifying your package.json file. If a lint script is specified and does not start with the string "jshint" OR if you configure the hook to run specific scripts, and that list of scripts does not include "lint", the jshint configuration files will not be created.

For example:

{
  "name": "your_project",
  "description": "just an example",
  "scripts": {
    "lint": "some_other_linter ."
  }
}

OR

{
  "name": "your_project",
  "description": "just an example",
  "precommit": ["test"]
}

If you do not configure the hook with an array of scripts to run, it will default to ["lint", "validate", "test"] to maintain backwards compatibility with the old version of this hook. In addition, if a lint script is not specified, it will default to "jshint .". If a lint script is configured, it will not be overridden. If an array of scripts is configured, it will be used and there will be no default lint script.

{
  "name": "your_project",
  "description": "just an example",
  "scripts": {
    "validate": "./command/to/run",
    "test": "./other/command"
  }
}

The contents of the validate and test properties are the shell commands to perform those functions. Having these specified in your package.json also lends you the ability to be able to run them manually like so:

npm run-script validate
npm test

These scripts can be any shell executable commands, but must exit with a status code of 0 for success and 1 or greater for failure. The PATH environment variable used when executing these scripts will be similar to how npm configures it. That means if you npm install jshint locally to your project, you can put simply "jshint ." for your script rather than "./node_modules/.bin/jshint .".

You may configure what scripts will be run by the hook, by passing an array of script names to the "precommit" key in your package.json.

{
  "name": "your_project",
  "description": "just an example",
  "scripts": {
    "lint": "jshint --with --different-options",
    "validate": "./command/to/run",
    "test": "./other/command"
  },
  "precommit": ["lint", "test"]
}

This example would run only the lint and test scripts, in that order.

npm install precommit-hook

Everything else is automatic!

I recommend putting precommit-hook in your project's devDependencies to make sure that anyone who may be contributing to your project will have the hook installed.

{
  "name": "your_project",
  "description": "just an example",
  "scripts": {
    "validate": "./command/to/run",
    "test": "./other/command"
  },
  "devDependencies": {
    "precommit-hook": "latest"
  }
}

The default .jshintrc looks like the following:

{
  "node": true, // node environment 
 
  "curly": true, // enforce using curly braces around blocks 
  "latedef": true, // enforce defining a variable before using it 
  "quotmark": true, // allows either " or ' but you must be consistent 
  "undef": true, // error on use of  variables 
  "unused": true, // error on variables that are defined but never used 
  "trailing": true // error on trailing whitespace 
}

And the default .jshintignore contains only one line

node_modules

Like the project? Hate it? Just want to say hi? Find me on twitter @quitlahok

MIT