fix enabling accept encoding with whitespaces

Signed-off-by: Sercan Degirmenci <sercan@otsimo.com>

server.go

@@ -2119,7 +2119,11 @@ func ClientSupportedCompressors(ctx context.Context) ([]string, error) {
 		return nil, fmt.Errorf("failed to fetch the stream from the given context %v", ctx)
 	}
 
-	return strings.Split(stream.ClientAdvertisedCompressors(), ","), nil
+	values := strings.Split(stream.ClientAdvertisedCompressors(), ",")
+	for i, v := range values {
+		values[i] = strings.TrimSpace(v)
+	}
+	return values, nil
 }
 
 // SetTrailer sets the trailer metadata that will be sent when an RPC returns.
@@ -2169,7 +2173,7 @@ func validateSendCompressor(name, clientCompressors string) error {
 	}
 
 	for _, c := range strings.Split(clientCompressors, ",") {
-		if c == name {
+		if strings.TrimSpace(c) == name {
 			return nil // found match
 		}
 	}

test/compressor_test.go

@@ -566,6 +566,13 @@ func (s) TestClientSupportedCompressors(t *testing.T) {
 			),
 			want: []string{"gzip"},
 		},
+		{
+			desc: "With additional grpc-accept-encoding header with spaces between values",
+			ctx: metadata.AppendToOutgoingContext(ctx,
+				"grpc-accept-encoding", "identity, deflate",
+			),
+			want: []string{"gzip", "identity", "deflate"},
+		},
 	} {
 		t.Run(tt.desc, func(t *testing.T) {
 			ss := &stubserver.StubServer{