commit-msg

#!/usr/bin/env node

/**
 *
 * Git COMMIT-MSG hook for validating commit message
 *
 * To be validated commit's message requires:
 * - A '#' at message begining
 * - Uppercase chars afer '#'
 * - Digit chars afer uppercase chars
 * EX: #TASK-456: is a valid test message
 *
 * Regex Online Tester Link
 * @see https://regex101.com/r/gH8aW8/1
 *
 * Installation:
 * copy this file under '<project_name>/.git/hooks/'
 * renamed it 'commit-msg'
 *
 */
(function () {

    'use strict';

    var fs = require('fs'),
        util = require('util'),
        // constants
        END_LINE = '\n',
        MAX_LENGTH = 100,
        JIRA_PATTERN = /#(\[A-Z]+-[0-9]+)\s(.*)/g,
        // messages
        INVALID_HEAD = 'INVALID COMMIT MSG: ',
        COMMIT_MESSAGE_FILE = 'COMMIT_EDITMSG',
        TOO_LONG = 'is longer than %d characters !',
        GIT_LOG_FILE = 'logs/incorrect-commit-msgs',
        NOT_MATCH = 'does not match pattern "#<ticket> <message>"!',
        // variables
        commitMsg, commitMsgFile,

        // https://github.com/chalk/ansi-styles/blob/master/index.js
        // https://gist.github.com/sixertoy/f26c7177e84bbef9308c96da54325f66
        __getColor = function (msg, code) {
            return '\u001b[' + code + 'm' + msg + '\u001b[39m';
        },
        _red = function (msg) {
            return __getColor(msg, 31);
        },
        _white = function (msg) {
            return __getColor(msg, 37);
        },
        _yellow = function (msg) {
            return __getColor(msg, 33);
        },

        /**
         *
         * Log error in console
         *
         */
        error = function () {
            var msg = _red(INVALID_HEAD);
            msg += util.format.apply(null, arguments);
            console.error(msg);
            return -1;
        },

        /**
         *
         * Message Validation Function
         * Return -1 if message is not valid
         * 		- will log error in console
         * Return 0 if message is valid but has error like
         * 		- wrong ticket # for this git branch
         * Return 1 if message is valid
         *
         */
        _validateMessage = function (message) {
            var match, msg,
                indexof = message.indexOf('#');
            if (indexof !== -1 && indexof !== 0) {
                message = ('#' + message);
            }
            // check message length
            if (message.length > MAX_LENGTH) {
                msg = _yellow(TOO_LONG);
                msg += END_LINE;
                msg += _white('>  ' + MAX_LENGTH);
                return error(msg);
            }
            // check message pattern
            match = JIRA_PATTERN.exec(message);
            if (!match) {
                msg = _yellow(NOT_MATCH);
                msg += END_LINE;
                msg += _white('>  ' + message);
                return error(msg);
            }
            return 1;

        },

        /**
         *
         * Return first line of commit message
         *
         */
        _getfirstLineFromBuffer = function (buffer) {
            var firstLine = buffer.toString()
                .split(END_LINE)
                .shift();
            return firstLine;
        },

        /**
         *
         * Write error message in log file
         *
         */
        _writeLogFileError = function (commitMsgFile, commitMsg, cb) {
            try {
                // GIT file where to write error
                var incorrectLogFile = commitMsgFile.replace(COMMIT_MESSAGE_FILE, GIT_LOG_FILE);
                // write file
                fs.appendFile(incorrectLogFile, commitMsg + '\n', cb);
            } catch (e) {
                throw new Error(e.message);
            }
        };

    // GIT file containing current commit message
    commitMsgFile = process.argv[2];

    // read commit file to validate message
    fs.readFile(commitMsgFile, function (err, buffer) {
        // -1 is not valid
        // 0 contains errors
        // 1 is valid
        var isMessageValid = -1;
        // get file content
        commitMsg = _getfirstLineFromBuffer(buffer);
        isMessageValid = _validateMessage(commitMsg);
        // if message is valid
        // exit process without errors
        if (isMessageValid > 0) {
            process.exit(0);
        }
        // if message is not valid
        // will write error message in GIT log file
        // exit process with errors
        if (isMessageValid < 0) {
            _writeLogFileError(commitMsgFile, commitMsg, function () {
                process.exit(1);

            });
        }
    });

    // publish for testing
    // exports.validateMessage = _validateMessage;

}());