migrat/lib/MigratExecutor.js

A pluggable migration runner.

var async = require('async');
var chalk = require('chalk');
var figures = require('figures');
var Log = require('./Log.js');
var MigratProjectBridge = require('./MigratProjectBridge.js');
var MigratRunListPrinter = require('./MigratRunListPrinter.js');

module.exports = function MigratExecutor(project, plugins, runlist, options, writer, callback) {
	var context, bridge = new MigratProjectBridge(project, plugins);
	Log.options = options;

	async.series([
		function createContext(callback) {
			if (!project.context) {
				return callback();
			}
			project.context(function(err, _context) {
				context = _context;
				callback(err);
			});
		},
		function executeBeforeRunHook(callback) {
			bridge.executeHook('beforeRun', [runlist, callback]);
		},
		function executeRunList(callback) {
			if (!runlist.items) {
				Log.write('No applicable migrations were found\n');
				return callback();
			}
			async.eachSeries(runlist.items, function(item, callback) {
				async.series([
					function executeBeforeEachHook(callback) {
						bridge.executeHook('beforeEach', [item, callback]);
					},
					function executeItem(callback) {
						Log.write(MigratRunListPrinter.getString(item));
						if (item.method !== 'skip') {
							var fn = item.migration.methods[item.method];
							var cb = function(err) {
								if (err) Log.write(' ' + chalk.red(figures.cross));
								else Log.write(' ' + chalk.green(figures.tick));
								callback(err);
							};
							// async interface: (context?)
							if (fn.length < 2) {
								return (new Promise(function(resolve, reject) {
									Promise.resolve(fn(context)).then(resolve, reject);
								})).then(function() { cb() }, cb);
							}
							// callback interface: (context, callback)
							if (fn.length >= 2) return fn(context, cb);
						} else {
							Log.write(' ' + chalk.gray('(skipped)'));
							callback();
						}
					},
					function verifyItem(callback) {
						var check = item.migration.methods['check'];
						if (!check || item.method !== 'up') {
							return callback();
						}
						var cb = function(err) {
							if (err) Log.write(' but ' + chalk.red('failed verification'));
							else Log.write(' and ' + chalk.green('passed verification'));
							callback(err);
						};
						// async interface: (context?)
						if (check.length < 2) {
							return (new Promise(function(resolve, reject) {
								Promise.resolve(check(context))
									.then(resolve, reject);
							})).then(function() { cb() }, cb);
						}
						// callback interface: (context, callback)
						if (check.length >= 2) return check(context, cb);
					},
					function persistItemStatus(callback) {
						writer(item, callback);
					}
				], function(err) {
					Log.write('\n');
					err = err || null;
					async.series([
						function executeAfterEachHook(callback) {
							async.setImmediate(function() {
								bridge.executeHook('afterEach', [err, item, callback]);
							});
						}
					], function(_err) {
						callback(err || _err || null);
					});
				});

			}, callback);
		}
	], function(err) {
		err = err || null;
		async.series([
			function executeAfterRunHook(callback) {
				async.setImmediate(function () {
					bridge.executeHook('afterRun', [err, runlist, callback]);
				});
			}
		], function(_err) {
			callback(err || _err || null);
		});
	});
};