Support CDP response previews for chunked data (#52331)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52331

Updates the iOS inputs to `NetworkReporter` to support incremental string data HTTP responses (`Transfer-Encoding: chunked`).

This means that incremental responses, such as Metro bundle requests, can be displayed as previews in React Native DevTools.

Changelog: [Internal]

Reviewed By: hoxyq

Differential Revision: D77457109

fbshipit-source-id: 00a622dbac97c38e07c67b5ee3661c8d586f6fe1

packages/react-native/Libraries/Network/RCTInspectorNetworkReporter.h

@@ -52,9 +52,27 @@
  */
 + (void)reportResponseEnd:(NSNumber *)requestId encodedDataLength:(int)encodedDataLength;
 
+/**
+ * Report when a network request has failed.
+ *
+ * - Corresponds to `Network.loadingFailed` in CDP.
+ */
++ (void)reportRequestFailed:(NSNumber *)requestId;
+
 /**
  * Store response body preview. This is an optional reporting method, and is a
  * no-op if CDP debugging is disabled.
  */
 + (void)maybeStoreResponseBody:(NSNumber *)requestId data:(NSData *)data base64Encoded:(bool)base64Encoded;
+
+/**
+ * Incrementally store a response body preview, when a string response is
+ * received in chunks. Buffered contents will be flushed to `NetworkReporter`
+ * with `reportResponseEnd`.
+ *
+ * As with `maybeStoreResponseBody`, calling this method is optional and a
+ * no-op if CDP debugging is disabled.
+ */
++ (void)maybeStoreResponseBodyIncremental:(NSNumber *)requestId data:(NSString *)data;
+
 @end

packages/react-native/Libraries/Network/RCTInspectorNetworkReporter.mm

@@ -45,6 +45,13 @@ std::string convertRequestBodyToStringTruncated(NSURLRequest *request)
 } // namespace
 #endif
 
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+
+// Dictionary to buffer incremental response bodies (CDP debugging active only)
+static const NSMutableDictionary<NSNumber *, NSMutableString *> *responseBuffers = nil;
+
+#endif
+
 @implementation RCTInspectorNetworkReporter {
 }
 
@@ -86,6 +93,31 @@ std::string convertRequestBodyToStringTruncated(NSURLRequest *request)
 + (void)reportResponseEnd:(NSNumber *)requestId encodedDataLength:(int)encodedDataLength
 {
   NetworkReporter::getInstance().reportResponseEnd(requestId.stringValue.UTF8String, encodedDataLength);
+
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: Check for buffered response body and flush to NetworkReporter
+  if (responseBuffers != nullptr) {
+    NSMutableString *buffer = responseBuffers[requestId];
+    if (buffer != nullptr) {
+      if (buffer.length > 0) {
+        NetworkReporter::getInstance().storeResponseBody(
+            requestId.stringValue.UTF8String, RCTStringViewFromNSString(buffer), false);
+      }
+      [responseBuffers removeObjectForKey:requestId];
+    }
+  }
+#endif
+}
+
+// TODO(T218584924): Implement and report to NetworkReporter
++ (void)reportRequestFailed:(NSNumber *)requestId
+{
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: Clear buffer for request
+  if (responseBuffers != nullptr) {
+    [responseBuffers removeObjectForKey:requestId];
+  }
+#endif
 }
 
 + (void)maybeStoreResponseBody:(NSNumber *)requestId data:(id)data base64Encoded:(bool)base64Encoded
@@ -115,4 +147,29 @@ std::string convertRequestBodyToStringTruncated(NSURLRequest *request)
   }
 #endif
 }
+
++ (void)maybeStoreResponseBodyIncremental:(NSNumber *)requestId data:(NSString *)data
+{
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: Buffer incremental response body contents
+  auto &networkReporter = NetworkReporter::getInstance();
+  if (!networkReporter.isDebuggingEnabled()) {
+    return;
+  }
+
+  if (responseBuffers == nullptr) {
+    responseBuffers = [NSMutableDictionary dictionary];
+  }
+
+  // Get or create buffer for this requestId
+  NSMutableString *buffer = responseBuffers[requestId];
+  if (buffer == nullptr) {
+    buffer = [NSMutableString string];
+    responseBuffers[requestId] = buffer;
+  }
+
+  [buffer appendString:data];
+#endif
+}
+
 @end

packages/react-native/Libraries/Network/RCTNetworking.mm

@@ -627,9 +627,9 @@ RCT_EXPORT_MODULE()
       incrementalDataBlock = ^(NSData *data, int64_t progress, int64_t total) {
         NSUInteger initialCarryLength = incrementalDataCarry.length;
 
-        NSString *responseString = [RCTNetworking decodeTextData:data
-                                                    fromResponse:task.response
-                                                   withCarryData:incrementalDataCarry];
+        id responseString = [RCTNetworking decodeTextData:data
+                                             fromResponse:task.response
+                                            withCarryData:incrementalDataCarry];
         if (!responseString) {
           RCTLogWarn(@"Received data was not a string, or was not a recognised encoding.");
           return;
@@ -643,6 +643,9 @@ RCT_EXPORT_MODULE()
           @(total)
         ];
 
+        if (facebook::react::ReactNativeFeatureFlags::enableNetworkEventReporting()) {
+          [RCTInspectorNetworkReporter maybeStoreResponseBodyIncremental:task.requestID data:responseString];
+        }
         [weakSelf sendEventWithName:@"didReceiveNetworkIncrementalData" body:responseJSON];
       };
     } else {
@@ -668,7 +671,11 @@ RCT_EXPORT_MODULE()
         @[ task.requestID, RCTNullIfNil(error.localizedDescription), error.code == kCFURLErrorTimedOut ? @YES : @NO ];
 
     if (facebook::react::ReactNativeFeatureFlags::enableNetworkEventReporting()) {
-      [RCTInspectorNetworkReporter reportResponseEnd:task.requestID encodedDataLength:data.length];
+      if (error != nullptr) {
+        [RCTInspectorNetworkReporter reportRequestFailed:task.requestID];
+      } else {
+        [RCTInspectorNetworkReporter reportResponseEnd:task.requestID encodedDataLength:data.length];
+      }
     }
     [strongSelf sendEventWithName:@"didCompleteNetworkResponse" body:responseJSON];
     [strongSelf->_tasksByRequestID removeObjectForKey:task.requestID];