Fix Networking to receive data for POST requests (#3940)

ryanwilson · web-flow · commit c2959919556b · 2019-09-27T16:45:27.000-04:00
* Fix Networking to receive data for POST requests

Currently,  GULNetworking doesn't receive the data when sending a POST request. 

Tracked internally at b/141712804

* Added unit tests.

* Update to handle the small data increments.
diff --git a/GoogleUtilities/Example/Tests/Network/GULNetworkTest.m b/GoogleUtilities/Example/Tests/Network/GULNetworkTest.m
@@ -130,6 +130,10 @@ - (void)testSessionNetwork_POST_foreground {
                        queue:_backgroundQueue
       usingBackgroundSession:NO
            completionHandler:^(NSHTTPURLResponse *response, NSData *data, NSError *error) {
+             XCTAssertNotNil(data);
+             NSString *responseBody = [[NSString alloc] initWithData:data
+                                                            encoding:NSUTF8StringEncoding];
+             XCTAssertEqualObjects(responseBody, @"<html><body>Hello, World!</body></html>");
              [self verifyResponse:response error:error];
              [self verifyRequest];
              XCTAssertFalse(self->_network.hasUploadInProgress, "There must be no pending request");
@@ -317,6 +321,10 @@ - (void)testSessionNetwork_POST_background {
                        queue:_backgroundQueue
       usingBackgroundSession:YES
            completionHandler:^(NSHTTPURLResponse *response, NSData *data, NSError *error) {
+             XCTAssertNotNil(data);
+             NSString *responseBody = [[NSString alloc] initWithData:data
+                                                            encoding:NSUTF8StringEncoding];
+             XCTAssertEqualObjects(responseBody, @"<html><body>Hello, World!</body></html>");
              [self verifyResponse:response error:error];
              [self verifyRequest];
              XCTAssertFalse(self->_network.hasUploadInProgress, "There must be no pending request");
diff --git a/GoogleUtilities/Network/GULNetworkURLSession.m b/GoogleUtilities/Network/GULNetworkURLSession.m
@@ -22,8 +22,9 @@
 #import "Private/GULNetworkMessageCode.h"
 
 @interface GULNetworkURLSession () <NSURLSessionDelegate,
-                                    NSURLSessionTaskDelegate,
-                                    NSURLSessionDownloadDelegate>
+                                    NSURLSessionDataDelegate,
+                                    NSURLSessionDownloadDelegate,
+                                    NSURLSessionTaskDelegate>
 @end
 
 @implementation GULNetworkURLSession {
@@ -221,6 +222,24 @@ - (nullable NSString *)sessionIDFromAsyncGETRequest:(NSURLRequest *)request
   return _sessionID;
 }
 
+#pragma mark - NSURLSessionDataDelegate
+
+/// Called by the NSURLSession when the data task has received some of the expected data.
+/// Once the session is completed, URLSession:task:didCompleteWithError will be called and the
+/// completion handler will be called with the downloaded data.
+- (void)URLSession:(NSURLSession *)session
+          dataTask:(NSURLSessionDataTask *)dataTask
+    didReceiveData:(NSData *)data {
+  @synchronized(self) {
+    NSMutableData *mutableData = [[NSMutableData alloc] init];
+    if (_downloadedData) {
+      mutableData = _downloadedData.mutableCopy;
+    }
+    [mutableData appendData:data];
+    _downloadedData = mutableData;
+  }
+}
+
 #pragma mark - NSURLSessionTaskDelegate
 
 /// Called by the NSURLSession once the download task is completed. The file is saved in the
