migrating repo to Bodyrep org

node_modules/mongoose/lib/promise.js

@@ -0,0 +1,151 @@
+
+/*!
+ * Module dependencies.
+ */
+
+var util = require('./utils');
+var EventEmitter = util.EventEmitter;
+
+/**
+ * Promise constructor.
+ *
+ * @param {Function} back a callback+errback that accepts `fn(err, ...){}` as signature
+ * @inherits NodeJS EventEmitter http://nodejs.org/api/events.html#events_class_events_eventemitter
+ * @event `err`: Emits when the promise resolves to an error.
+ * @event `complete`: Emits when the promise resolves sucessfully.
+ * @api public
+ */
+
+function Promise (back) {
+  this.emitted = {};
+  if ('function' == typeof back)
+    this.addBack(back);
+};
+
+/*!
+ * Inherits from EventEmitter.
+ */
+
+Promise.prototype.__proto__ = EventEmitter.prototype;
+
+/**
+ * Adds `listener` to the `event`.
+ *
+ * If `event` is either `error` or `complete` and the event has already been emitted, the`listener` is called immediately and passed the results of the original emitted event.
+ *
+ * @param {Event} event
+ * @param {Function} callback
+ * @return {Promise} this
+ * @api public
+ */
+
+Promise.prototype.on = function (event, callback) {
+  if (this.emitted[event])
+    callback.apply(this, this.emitted[event]);
+  else
+    EventEmitter.prototype.on.call(this, event, callback);
+
+  return this;
+};
+
+/**
+ * Keeps track of emitted events to run them on `on`.
+ *
+ * @api private
+ */
+
+Promise.prototype.emit = function (event) {
+  // ensures a promise can't be complete() or error() twice
+  if (event == 'err' || event == 'complete'){
+    if (this.emitted.err || this.emitted.complete) {
+      return this;
+    }
+    this.emitted[event] = util.args(arguments, 1);
+  }
+
+  return EventEmitter.prototype.emit.apply(this, arguments);
+};
+
+/**
+ * Shortcut for emitting the `complete` event.
+ *
+ * @api public
+ */
+
+Promise.prototype.complete = function () {
+  var args = util.args(arguments);
+  return this.emit.apply(this, ['complete'].concat(args));
+};
+
+/**
+ * Shortcut for emitting the `err` event.
+ *
+ * @api public
+ * @return {Promise}
+ */
+
+Promise.prototype.error = function (err) {
+  if (!(err instanceof Error)) err = new Error(err);
+  return this.emit('err', err);
+};
+
+/**
+ * Shortcut for `.on('complete', fn)`.
+ *
+ * @return {Promise}
+ * @api public
+ */
+
+Promise.prototype.addCallback = function (fn) {
+  return this.on('complete', fn);
+};
+
+/**
+ * Shortcut for `.on('err', fn)`.
+ *
+ * @return {Promise}
+ * @api public
+ */
+
+Promise.prototype.addErrback = function (fn) {
+  return this.on('err', fn);
+};
+
+/**
+ * Adds a single function that's both a callback and errback.
+ *
+ * @param {Function} fn
+ * @return {Promise}
+ */
+
+Promise.prototype.addBack = function (fn) {
+  this.on('err', function(err){
+    fn.call(this, err);
+  });
+
+  this.on('complete', function(){
+    var args = util.args(arguments);
+    fn.apply(this, [null].concat(args));
+  });
+
+  return this;
+};
+
+/**
+ * Sugar for handling cases where you may be resolving to either an error condition or a success condition.
+ *
+ * @param {Error} err optional error or null
+ * @param {Object} val value to complete the promise with
+ * @api public
+ */
+
+Promise.prototype.resolve = function (err, val) {
+  if (err) return this.error(err);
+  return this.complete(val);
+};
+
+/*!
+ * Module exports.
+ */
+
+module.exports = Promise;