precommit-hook/bin/pre-commit

#!/usr/bin/env node

// requires
var exec = require('child_process').exec;
var path = require('path');

// some status strings
var fail = '\x1B[31mfailed!\x1B[39m';
var ok = '\x1B[32mok\x1B[39m';
var notfound = '\x1B[31mfailed\x1B[31m (no script found)';
var notfoundDefault = '\x1B[33mn/a\x1B[39m (no script found)';

// longest name, for padding
var longest = 0;

// config
var projectRoot = '{{projectRoot}}'; // lame templating so this gets populated correctly
var package = require(path.join(projectRoot, 'package.json'));
var scripts = package.scripts;
var config = package.precommit;

// set up environment
var pathKey;
var pathSep = process.platform === 'win32' ? ';' : ':';
var env = {};
for (var key in process.env) {
    if (key.toLowerCase() === 'path') {
        pathKey = key;
    }

    env[key] = process.env[key];
}
env[pathKey] = path.join(projectRoot, 'node_modules', '.bin') + pathSep + env[pathKey];

// run the command for the given property
function runCmd(name, done) {
    done = done || process.exit;

    var pad = '';
    for (var i = 0, il = longest - name.length; i < il; ++i) {
        pad += ' ';
    }
    process.stdout.write('running ' + name + ': ' + pad);

    if (!scripts[name]) {
        console.log(notfound);
        exit(1, process.exit);
    }

    var cmd = (process.platform === 'win32' ? 'cmd /c ' : 'sh -c ') + JSON.stringify(scripts[name]);
    exec(cmd, { cwd: projectRoot, env: env }, function (err, stdout, stderr) {
        if (err) {
            console.log(fail);
            console.log(stdout);
            console.log(stderr);
            exit(err.code, process.exit);
        } else {
            console.log(ok);
            exit(0, done);
        }
    });
}

// this method shamelessly adapted from https://github.com/cowboy/node-exit
function exit(code, callback) {
    var streams = [process.stdout, process.stderr];
    var drainCount = 0;

    function tryToExit() {
        if (drainCount === streams.length) {
            callback(code);
        }
    }

    streams.forEach(function (stream) {
        if (stream.bufferSize === 0) {
            drainCount++;
        } else {
            stream.write('', 'utf-8', function () {
                drainCount++;
                tryToExit();
            });

            stream.write = function () {};
        }
    });

    tryToExit();
}

if (!config || !config.length) {
    config = ['lint'];
    scripts = scripts || {};
    scripts.lint = scripts.lint || 'jshint .';
    ['validate', 'test'].forEach(function (elem) {
        if (scripts[elem]) {
            config.push(elem);
        } else {
            console.log(elem + ': ' + notfoundDefault);
        }
    });
}

var tasks = [];

config.forEach(function (cmd, i) {
    longest = (longest < cmd.length) ? cmd.length : longest;
    var task = runCmd.bind(null, cmd);
    tasks[i] = function () {
        task.call(null, tasks[i + 1]);
    };
});

console.log('running pre-commit checks...');
tasks[0]();