chg/lib/chg.js

/*
 * chg
 * https://github.com/heff/chg
 *
 * Copyright (c) 2014 heff
 * Licensed under the Apache license.
 */

'use strict';

var chg = module.exports = {};

var fs = require('fs');
var shell = require('shelljs');
var moment = require('moment');
var semver = require('semver');

var changeLogFile = 'CHANGELOG.md';
var unreleasedTitle = '## HEAD (Unreleased)\n';
var noItems = '_(none)_';
var divider = '--------------------\n\n';

var ERR_NO_CHANGELOG = changeLogFile+' does not exist. Change to the directory where it does exist, or run `init` to create one in the current directory.';

function defCallback(){}

function getChangeLog(){
  if (!fs.existsSync(changeLogFile)) {
    return null;
  }
  return fs.readFileSync(changeLogFile, 'utf8');
}

chg.init = function(options, callback){
  options = options || {};
  callback = callback || defCallback;

  if (fs.existsSync(changeLogFile)){
    return callback(changeLogFile + ' already exists');
  }

  var contents = 'CHANGELOG\n=========\n\n';
  contents += unreleasedTitle + noItems + '\n\n' + divider;

  fs.writeFileSync(changeLogFile, contents, 'utf8');

  callback(null, changeLogFile+' created');
};

chg.delete = function(options, callback){
  options = options || {};
  callback = callback || defCallback;

  if (fs.existsSync(changeLogFile)){
    shell.rm(changeLogFile);
    callback(null, changeLogFile+' deleted');
  } else {
    callback(changeLogFile+' does not exist');
  }
};

chg.add = function(line, options, callback){
  var contents, sections, top;

  options = options || {};
  callback = callback || defCallback;

  // get existing contents
  contents = getChangeLog();
  if (!contents) { 
    return callback(ERR_NO_CHANGELOG);
  }

  // if 'noItems' is there, remove it
  contents = contents.replace(unreleasedTitle + noItems + '\n', unreleasedTitle);

  // split on the divider including preceding newline
  sections = contents.split('\n'+divider);
  // add new line to the unreleased section
  top = sections[0] + '* ' + line + '\n\n';

  // combine new contents and write file
  contents = top + divider + sections[1];
  fs.writeFileSync(changeLogFile, contents, 'utf8');

  callback(null, 'Change added');
};

chg.release = function(version, options, callback){
  var date, contents, changes, title, pkgVersion;

  callback = callback || defCallback;
  options = options || {};
  date = options.date || moment().format('YYYY-MM-DD');
  version = version || options.version || null;

  if (!version) { 
    return callback('Version required'); 
  }

  // allow incrementing version for a release type
  if (['major','minor','patch'].indexOf(version) != -1) {
    if (fs.existsSync('./package.json')) {
      pkgVersion = require(process.cwd()+'/package.json').version;
      version = semver.inc(pkgVersion, version);
    } else {
      callback('No package.json was found');
    }
  }

  // get existing contents
  contents = getChangeLog();
  if (!contents) { 
    return callback(ERR_NO_CHANGELOG);
  }

  // get everything after the unreleased title
  changes = contents.split(unreleasedTitle)[1];
  // get only the unreleased changes
  changes = changes.split('\n\n')[0];
  // replace unreleased changes with noItems
  contents = contents.replace(changes, noItems);

  // build new release title
  title = '##' + ' ' + version + ' ('+ date +')\n';
  // add title at the top of the release section
  contents = contents.replace(divider, divider + title + changes + '\n\n');

  fs.writeFileSync(changeLogFile, contents, 'utf8');

  callback(null, 'Changelog updated with new release');
};