From ec3622eb3d5fd52ad29ed14512e83784a40d5b54 Mon Sep 17 00:00:00 2001
From: Georgios Kalpakas <g.kalpakas@hotmail.com>
Date: Wed, 30 Sep 2015 16:56:48 +0300
Subject: [PATCH] fix($http): apply `transformResponse` when `data` is empty

Note, that (as a by-product of the previous implementation) only non-empty
data was passed through the `transformResponse` pipeline. This is no
longer the case.

When using a custom `transformResponse` function, one should make sure it
can also handle an empty (i.e. falsy) `data` argument appropriatelly.

Fixes #12976
---
 src/ng/http.js      |  7 ++-----
 test/ng/httpSpec.js | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/ng/http.js b/src/ng/http.js
index 12e2fd3020b6..0148515294bd 100644
--- a/src/ng/http.js
+++ b/src/ng/http.js
@@ -999,11 +999,8 @@ function $HttpProvider() {
       function transformResponse(response) {
         // make a copy since the response must be cacheable
         var resp = extend({}, response);
-        if (!response.data) {
-          resp.data = response.data;
-        } else {
-          resp.data = transformData(response.data, response.headers, response.status, config.transformResponse);
-        }
+        resp.data = transformData(response.data, response.headers, response.status,
+                                  config.transformResponse);
         return (isSuccess(response.status))
           ? resp
           : $q.reject(resp);
diff --git a/test/ng/httpSpec.js b/test/ng/httpSpec.js
index 168305eab34f..7942dd9d567e 100644
--- a/test/ng/httpSpec.js
+++ b/test/ng/httpSpec.js
@@ -1391,6 +1391,25 @@ describe('$http', function() {
           expect(callback).toHaveBeenCalledOnce();
           expect(callback.mostRecentCall.args[0]).toBe('RESP-FIRST:V1');
         });
+
+
+        it('should apply `transformResponse` even if the response data is empty', function(data) {
+          var callback = jasmine.createSpy('transformResponse');
+          var config = {transformResponse: callback};
+
+          $httpBackend.expect('GET', '/url1').respond(200, undefined);
+          $httpBackend.expect('GET', '/url2').respond(200, null);
+          $httpBackend.expect('GET', '/url3').respond(200, '');
+          $http.get('/url1', config);
+          $http.get('/url2', config);
+          $http.get('/url3', config);
+          $httpBackend.flush();
+
+          expect(callback.callCount).toBe(3);
+          expect(callback.calls[0].args[0]).toBe(undefined);
+          expect(callback.calls[1].args[0]).toBe(null);
+          expect(callback.calls[2].args[0]).toBe('');
+        });
       });
     });