Unfinished GitHub patch helper written in JavaScript/Node

README

I started writing this program but then got bored and decided to
re-write it in Go. This is my unfinished JavaScript variant.
See https://github.com/antonkovalyov/r2go for more information.

r2.js

var https   = require('https');
var cliff   = require('cliff');
var colors  = require('colors');
var request = require('request');
var exec    = require('child_process').exec;
var spawn   = require('child_process').spawn;
var tty     = require('tty');
var fs      = require('fs');
var path    = require('path');

var github = Object.create({
	repoUser: '',
	repoName: '',

	get: function (method, callback) {
		var host = 'https://api.github.com';
		var path = method.replace(':user', this.repoUser)
		path = path.replace(':repo', this.repoName);

		request(host + path, function (err, res, body) {
			if (err)
				panic('Request failed. Reason: ' + err.message);

			callback(JSON.parse(body));
		});
	}
});

var git = Object.create({
	path: '',
	template: '',

	exec: function (commands, callback) {
		var options = { cwd: this.path };

		function execOne(cmd) {
			exec(cmd, options, function (err, stdout, stderr) {
				if (err)
					panic('Git command failed. Reason: ' + err.message);

				cmd = commands.shift();
				if (!cmd)
					return void callback(stdout);

				execOne(cmd);
			});
		}

		if (commands.length === 0)
			return;

		execOne(commands.shift());
	},

	execInteractive: function (cmd, opts, callback) {
		var prog;

		process.stdin.pause();
		tty.setRawMode(false);

		prog = spawn(cmd, opts, {
			customFds: [ 0, 1, 2 ]
		});

		prog.on('exit', function () {
			tty.setRawMode(true);
			process.stdin.resume();
			callback();
		});
	}
});

function listPullRequests(data) {
	var rows = [];

	for (var i = 0; i < data.length; i++) {
		rows.push([
			'GH-' + data[i].number,
			data[i].state === 'open' ? data[i].title.green : data[i].title.red
		]);
	}

	console.log(cliff.stringifyRows(rows));
}


function list() {
	github.get('/repos/:user/:repo/pulls', function (pullRequests) {
		var rows = [];

		if (!pullRequests.length)
			return;

		pullRequests.forEach(function (pr) {
			rows.push([ 'GH-' + pr.number, pr.title ]);
		});

		console.log(cliff.stringifyRows(rows));
	});
}

function diff(id) {
	if (!id)
		panic("Pull request number is required for 'r2 diff' to work.");

	github.get('/repos/:user/:repo/pulls/' + id, function (pullRequest) {
		request(pullRequest.diff_url, function (err, res, body) {
			var lines = body.split('\n');

			lines.forEach(function (line, index) {
				if (line.match(/^(diff|index|\-\-\-|\+\+\+).+$/))
					lines[index] = line.white;
				else if (line.match(/^@@.+$/))
					lines[index] = line.cyan;
				else if (line.match(/^\+.+$/))
					lines[index] = line.green;
				else if (line.match(/^\-.+$/))
					lines[index] = line.red;
				else
					lines[index] = line.grey;
			});

			console.log(lines.join('\n'));
		});
	});
}


function patch(id) {
	if (!id)
		panic("Pull request number is required for 'r2 patch' to work.");

	github.get('/repos/:user/:repo/pulls/' + id, function (pr) {
		var commands = [
			'git checkout -b gh' + id + ' master',
			'git pull ' + pr.head.repo.clone_url + ' ' + pr.head.ref,
		];

		git.exec(commands, function () {
			console.log('Patch has been successfully applied.'.green);
		});
	});
}


function land(id) {
	if (!id)
		panic("Pull request number is required for 'r2 land' to work.");

	function merge(branch, author) {
		var commands = [
			'git checkout master',
			'git merge --squash --no-commit ' + branch
		];

		process.stdout.write('Landing GH-' + id + ': ');
		git.exec(commands, function () {
			'git commit -t ' + git.template + '--author="' + author + '"'
			git.execInteractive('git', [ 'commit', '-t ' + git.template, '--author="' + author + '"' ], function () {
				console.log('Done.'.green);
				process.exit(0);
			});
		});
	}

	var commands = [
		'git log gh' + id + '^..gh' + id + ' --pretty=format:"%an <%ae>"'
	];

	git.exec(commands, function (author) {
		merge('gh' + id, author);
	});
}


function help() {
	console.log('r2: a command line tool for managing pull requests on GitHub');
	console.log();

	var out = cliff.stringifyRows([
		[ 'help'.blue,  'Show this help.' ],
		[ 'list'.blue,  'Show all open pull requests.' ],
		[ 'patch'.blue, 'Apply changes in the pull request to a working copy.' ],
		[ 'land'.blue,  'Accept and merge changes from the pull requests.' ]
	]);

	console.log(out);
}

function panic(msg) {
	console.log(msg.red);
	process.exit(1);
}

function main() {
	var commands = {
		'help':  help,
		'list':  list,
		'diff':  diff,
		'patch': patch,
		'land':  land
	};

	if (process.argv.length < 3)
		return void help();

	var cmd = process.argv[2];
	if (commands[cmd] === undefined)
		panic('Unknown command: ' + cmd + '.');

	fs.readFile(path.join(process.cwd(), '/.r2config'), function (err, data) {
		var config;

		if (err)
			panic("Failed to parse '.r2config'. Reason: " + err.message);

		try {
			config = JSON.parse(data);
		} catch (err) {
			panic("Failed to parse '.r2config'. Reason: " + err.message);
		}

		if (!config.repo)
			panic('Object repo is not set.');

		git.path = process.cwd();
		git.template = path.join(path.dirname(process.argv[1]), '/res/commit-template.txt');
		github.repoUser = config.repo.user || panic('Variable repo.user is not set.');
		github.repoName = config.repo.name || panic('Variable repo.name is not set.');
		github.username = config.username;
		github.password = config.password;
		commands[cmd].apply({}, process.argv.slice(3));
	});
}

main();