Put both headers and trailers in the error.userInfo

src/objective-c/GRPCClient/GRPCCall.h

@@ -48,8 +48,10 @@
 #import <Foundation/Foundation.h>
 #import <RxLibrary/GRXWriter.h>
 
-// Key used in |NSError|'s |userInfo| dictionary to store the response metadata sent by the server.
-extern id const kGRPCStatusMetadataKey;
+// Keys used in |NSError|'s |userInfo| dictionary to store the response headers and trailers sent by
+// the server.
+extern id const kGRPCHeadersKey;
+extern id const kGRPCTrailersKey;
 
 // Represents a single gRPC remote call.
 @interface GRPCCall : GRXWriter

src/objective-c/GRPCClient/GRPCCall.m

@@ -42,7 +42,8 @@
 #import "private/NSDictionary+GRPC.h"
 #import "private/NSError+GRPC.h"
 
-NSString * const kGRPCStatusMetadataKey = @"io.grpc.StatusMetadataKey";
+NSString * const kGRPCHeadersKey = @"io.grpc.HeadersKey";
+NSString * const kGRPCTrailersKey = @"io.grpc.TrailersKey";
 
 @interface GRPCCall () <GRXWriteable>
 // Make them read-write.
@@ -331,11 +332,15 @@ NSString * const kGRPCStatusMetadataKey = @"io.grpc.StatusMetadataKey";
         if (error.userInfo) {
           [userInfo addEntriesFromDictionary:error.userInfo];
         }
-        userInfo[kGRPCStatusMetadataKey] = strongSelf.responseTrailers;
+        userInfo[kGRPCTrailersKey] = strongSelf.responseTrailers;
         // TODO(jcanizales): The C gRPC library doesn't guarantee that the headers block will be
         // called before this one, so an error might end up with trailers but no headers. We
-        // shouldn't call finishWithError until ater both blocks are called. It is when this is done
-        // that we can provide a merged view of response headers and trailers in a thread-safe way.
+        // shouldn't call finishWithError until ater both blocks are called. It is also when this is
+        // done that we can provide a merged view of response headers and trailers in a thread-safe
+        // way.
+        if (strongSelf.responseHeaders) {
+          userInfo[kGRPCHeadersKey] = strongSelf.responseHeaders;
+        }
         error = [NSError errorWithDomain:error.domain code:error.code userInfo:userInfo];
       }
       [strongSelf finishWithError:error];

src/objective-c/tests/GRPCClientTests.m

@@ -168,11 +168,13 @@ static ProtoMethod *kUnaryCallMethod;
   } completionHandler:^(NSError *errorOrNil) {
     XCTAssertNotNil(errorOrNil, @"Finished without error!");
     XCTAssertEqual(errorOrNil.code, 16, @"Finished with unexpected error: %@", errorOrNil);
-    XCTAssertEqualObjects(call.allResponseMetadata, errorOrNil.userInfo[kGRPCStatusMetadataKey],
-                          @"Metadata in the NSError object and call object differ.");
+    XCTAssertEqualObjects(call.responseHeaders, errorOrNil.userInfo[kGRPCHeadersKey],
+                          @"Headers in the NSError object and call object differ.");
+    XCTAssertEqualObjects(call.responseTrailers, errorOrNil.userInfo[kGRPCTrailersKey],
+                          @"Trailers in the NSError object and call object differ.");
     NSString *challengeHeader = call.oauth2ChallengeHeader;
     XCTAssertGreaterThan(challengeHeader.length, 0,
-                         @"No challenge in response headers %@", call.allResponseMetadata);
+                         @"No challenge in response headers %@", call.responseHeaders);
     [expectation fulfill];
   }];