fix($http): JSON parse failure

Fixes angular#15695

Author: chirag64

docs/content/error/$http/baddata.ngdoc

@@ -0,0 +1,13 @@
+@ngdoc error
+@name $http:baddata
+@fullName Bad JSON Data
+@description
+
+This error occurs when the data parameter passed to the {@link ng.$http `defaultHttpResponseTransform`} service is not a valid JSON object.
+`defaultHttpResponseTransform` expects the first parameter as a valid JSON object if the second parameter of headers specifies a Content-Type of JSON.
+
+The error message should provide additional context such as the actual value of the parameter that was received.
+
+To resolve this error, make sure you pass a valid JSON data object to `defaultHttpResponseTransform`.
+
+For more information, see the {@link ng.$http `defaultHttpResponseTransform`} service API documentation.

src/ng/http.js

@@ -138,7 +138,11 @@ function defaultHttpResponseTransform(data, headers) {
     if (tempData) {
       var contentType = headers('Content-Type');
       if ((contentType && (contentType.indexOf(APPLICATION_JSON) === 0)) || isJsonLike(tempData)) {
-        data = fromJson(tempData);
+        try {
+          data = fromJson(tempData);
+        } catch (e) {
+          throw minErr('$http')('baddata', 'Data must be a valid JSON object. Received: {0}', data);
+        }
       }
     }
   }