Fix the equivalent of kriskowal#134 but for npost.

q.js

@@ -1573,7 +1573,12 @@ function nbind(callback /* thisp, ...args*/) {
  */
 exports.npost = npost;
 function npost(object, name, args) {
-    return napply(object[name], object, args);
+    var nodeArgs = array_slice(args);
+    var deferred = defer();
+    nodeArgs.push(deferred.makeNodeResolver());
+
+    post(object, name, nodeArgs).fail(deferred.reject);
+    return deferred.promise;
 }
 
 /**
@@ -1588,11 +1593,11 @@ function npost(object, name, args) {
  */
 exports.ninvoke = ninvoke;
 function ninvoke(object, name /*, ...args*/) {
-    var args = array_slice(arguments, 2);
+    var nodeArgs = array_slice(arguments, 2);
     var deferred = defer();
-    args.push(deferred.makeNodeResolver());
+    nodeArgs.push(deferred.makeNodeResolver());
 
-    post(object, name, args).fail(deferred.reject);
+    post(object, name, nodeArgs).fail(deferred.reject);
     return deferred.promise;
 }
 

spec/q-spec.js

@@ -1596,6 +1596,23 @@ describe("node support", function () {
             });
         });
 
+        it("rejects with thrown error", function () {
+            return Q.npost(obj, "errorThrower", [1, 2, 3])
+            .then(function (sum) {
+                expect(true).toBe(false);
+            }, function (_exception) {
+                expect(_exception).toBe(exception);
+            });
+        });
+
+        it("works on promises for objects with Node methods", function () {
+            return Q.resolve(obj)
+            .npost("method", [1, 2, 3])
+            .then(function (sum) {
+                expect(sum).toEqual(6);
+            });
+        });
+
     });
 
     describe("ninvoke", function (done) {