Merge pull request #74 from teddyzeenny/promises-aplus-tests

Make rsvp Promises/A+ spec-1.1 compliant

lib/rsvp/promise.js

@@ -61,12 +61,8 @@ var invokeCallback = function(type, promise, callback, event) {
     succeeded = true;
   }
 
-  if (objectOrFunction(value) && isFunction(value.then)) {
-    value.then(function(value) {
-      resolve(promise, value);
-    }, function(error) {
-      reject(promise, error);
-    });
+  if (handleThenable(promise, value)) {
+    return;
   } else if (hasCallback && succeeded) {
     resolve(promise, value);
   } else if (failed) {
@@ -111,24 +107,45 @@ Promise.prototype = {
 EventTarget.mixin(Promise.prototype);
 
 function resolve(promise, value) {
-
   if (promise === value) {
     fulfill(promise, value);
-  } else if (objectOrFunction(value) && isFunction(value.then)) {
-    value.then(function(val) {
-      if (value !== val) {
-        resolve(promise, val);
-      } else {
-        fulfill(promise, val);
-      }
-    }, function(val) {
-      reject(promise, val);
-    });
-  } else {
+  } else if (!handleThenable(promise, value)) {
     fulfill(promise, value);
   }
 }
 
+function handleThenable(promise, value) {
+  var then = null;
+
+  if (objectOrFunction(value)) {
+    try {
+      then = value.then;
+    } catch(e) {
+      reject(promise, e);
+      return true;
+    }
+
+    if (isFunction(then)) {
+      try {
+        then.call(value, function(val) {
+          if (value !== val) {
+            resolve(promise, val);
+          } else {
+            fulfill(promise, val);
+          }
+        }, function(val) {
+          reject(promise, val);
+        });
+      } catch (e) {
+        reject(promise, e);
+      }
+      return true;
+    }
+  }
+
+  return false;
+}
+
 function fulfill(promise, value) {
   config.async(function() {
     promise.trigger('promise:resolved', { detail: value });