Merge pull request #93 from stefanpenner/master

some a+ 1.1 spec fixes.

lib/rsvp/promise.js

@@ -10,7 +10,8 @@ function isFunction(x){
 }
 
 var Promise = function(resolver) {
-  var promise = this;
+  var promise = this,
+  resolved = false;
 
   if (typeof resolver !== 'function') {
     throw new TypeError('You must pass a resolver function as the sole argument to the promise constructor');
@@ -21,10 +22,14 @@ var Promise = function(resolver) {
   }
 
   var resolvePromise = function(value) {
+    if (resolved) { return; }
+    resolved = true;
     resolve(promise, value);
   };
 
   var rejectPromise = function(value) {
+    if (resolved) { return; }
+    resolved = true;
     reject(promise, value);
   };
 
@@ -83,9 +88,12 @@ var invokeCallback = function(type, promise, callback, event) {
 
 Promise.prototype = {
   constructor: Promise,
-  isFulfilled: undefined,
+
   isRejected: undefined,
-  isResolved: undefined,
+  isFulfilled: undefined,
+  rejectedReason: undefined,
+  fulfillmentValue: undefined,
+
   then: function(done, fail) {
     this.off('error', onerror);
 
@@ -126,20 +134,31 @@ function resolve(promise, value) {
 }
 
 function handleThenable(promise, value) {
-  var then = null;
+  var then = null,
+  resolved;
 
   try {
+    if (promise === value) {
+      throw new TypeError("A promises callback cannot return that same promise.");
+    }
+
     if (objectOrFunction(value)) {
       then = value.then;
 
       if (isFunction(then)) {
         then.call(value, function(val) {
+          if (resolved) { return true; }
+          resolved = true;
+
           if (value !== val) {
             resolve(promise, val);
           } else {
             fulfill(promise, val);
           }
         }, function(val) {
+          if (resolved) { return true; }
+          resolved = true;
+
           reject(promise, val);
         });
 
@@ -155,9 +174,6 @@ function handleThenable(promise, value) {
 }
 
 function fulfill(promise, value) {
-  if (promise.isResolved){ return; }
-  promise.isResolved = true;
-
   config.async(function() {
     promise.trigger('promise:resolved', { detail: value });
     promise.isFulfilled = true;
@@ -166,9 +182,6 @@ function fulfill(promise, value) {
 }
 
 function reject(promise, value) {
-  if (promise.isResolved){ return; }
-  promise.isResolved = true;
-
   config.async(function() {
     promise.trigger('promise:failed', { detail: value });
     promise.isRejected = true;