fix($http): don't convert FormData objects to JSON

This won't enable FormData uploads in itself, as the Content-Type is automatically set to application/json.

Closes #10373

src/.jshintrc

@@ -51,6 +51,7 @@
     "isWindow": false,
     "isScope": false,
     "isFile": false,
+    "isFormData": false,
     "isBlob": false,
     "isBoolean": false,
     "isPromiseLike": false,

src/Angular.js

@@ -45,6 +45,7 @@
   isWindow: true,
   isScope: true,
   isFile: true,
+  isFormData: true,
   isBlob: true,
   isBoolean: true,
   isPromiseLike: true,
@@ -566,6 +567,11 @@ function isFile(obj) {
 }
 
 
+function isFormData(obj) {
+  return toString.call(obj) === '[object FormData]';
+}
+
+
 function isBlob(obj) {
   return toString.call(obj) === '[object Blob]';
 }

src/ng/http.js

@@ -142,7 +142,7 @@ function $HttpProvider() {
 
     // transform outgoing request data
     transformRequest: [function(d) {
-      return isObject(d) && !isFile(d) && !isBlob(d) ? toJson(d) : d;
+      return isObject(d) && !isFile(d) && !isBlob(d) && !isFormData(d) ? toJson(d) : d;
     }],
 
     // default headers

test/ng/httpSpec.js

@@ -991,6 +991,15 @@ describe('$http', function() {
           $http({ method: 'POST', url: '/url', data: blob });
         });
 
+        it('should ignore FormData objects', function() {
+          if (!window.FormData) return;
+
+          var formData = new FormData();
+          formData.append('angular', 'is great');
+
+          $httpBackend.expect('POST', '/url', '[object FormData]').respond('');
+          $http({ method: 'POST', url: '/url', data: formData });
+        });
 
         it('should have access to request headers', function() {
           $httpBackend.expect('POST', '/url', 'header1').respond(200);