protobuf: StatusProto#fromStatusAndTrailers fall-back use status (#6278)

grpc · Oct 15, 2019 · eda5e2e · eda5e2e
1 parent adcfb3e
commit eda5e2e
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Showing 2 changed files with 28 additions and 15 deletions.
diff --git a/protobuf/src/main/java/io/grpc/protobuf/StatusProto.java b/protobuf/src/main/java/io/grpc/protobuf/StatusProto.java
@@ -147,14 +147,16 @@ public static com.google.rpc.Status fromThrowable(Throwable t) {
   }
 
   /**
-   * Extracts the google.rpc.Status from trailers, and makes sure they match the gRPC
-   * {@code status}.
+   * Extracts the {@code google.rpc.Status} from trailers, and makes sure they match the gRPC
+   * {@code status}. If the trailers do not contain a {@code google.rpc.Status}, it uses
+   * {@code status} param to generate a {@code google.rpc.Status}.
    *
-   * @return the embedded google.rpc.Status or {@code null} if it is not present.
+   * @return the embedded google.rpc.Status
    * @since 1.11.0
    */
-  @Nullable
-  public static com.google.rpc.Status fromStatusAndTrailers(Status status, Metadata trailers) {
+  public static com.google.rpc.Status fromStatusAndTrailers(
+      Status status, @Nullable Metadata trailers) {
+    checkNotNull(status, "status");
     if (trailers != null) {
       com.google.rpc.Status statusProto = trailers.get(STATUS_DETAILS_KEY);
       if (statusProto != null) {
@@ -164,6 +166,12 @@ public static com.google.rpc.Status fromStatusAndTrailers(Status status, Metadat
         return statusProto;
       }
     }
-    return null;
+    // fall-back to status, this is useful if the error is local. e.g. Server is unavailable.
+    com.google.rpc.Status.Builder statusBuilder = com.google.rpc.Status.newBuilder()
+        .setCode(status.getCode().value());
+    if (status.getDescription() != null) {
+      statusBuilder.setMessage(status.getDescription());
+    }
+    return statusBuilder.build();
   }
 }
diff --git a/protobuf/src/test/java/io/grpc/protobuf/StatusProtoTest.java b/protobuf/src/test/java/io/grpc/protobuf/StatusProtoTest.java
@@ -126,20 +126,25 @@ public void toStatusException_shouldThrowIfStatusCodeInvalid() throws Exception
   }
 
   @Test
-  public void fromThrowable_shouldReturnNullIfTrailersAreNull() {
-    Status status = Status.fromCodeValue(0);
+  public void fromThrowable_runtimeException_shouldReturnDerivedStatusIfTrailersAreNull() {
+    Status status = Status.UNAVAILABLE.withDescription("not available");
 
-    assertNull(StatusProto.fromThrowable(status.asRuntimeException()));
-    assertNull(StatusProto.fromThrowable(status.asException()));
+    com.google.rpc.Status statusFromThrowable =
+        StatusProto.fromThrowable(status.asRuntimeException());
+
+    assertEquals(statusFromThrowable.getCode(), status.getCode().value());
+    assertEquals(statusFromThrowable.getMessage(), status.getDescription());
   }
 
   @Test
-  public void fromThrowable_shouldReturnNullIfStatusDetailsKeyIsMissing() {
-    Status status = Status.fromCodeValue(0);
-    Metadata emptyMetadata = new Metadata();
+  public void fromThrowable_exception_shouldReturnDerivedStatusIfTrailersAreNull() {
+    Status status = Status.UNAVAILABLE.withDescription("not available");
+
+    com.google.rpc.Status statusFromThrowable =
+        StatusProto.fromThrowable(status.asException());
 
-    assertNull(StatusProto.fromThrowable(status.asRuntimeException(emptyMetadata)));
-    assertNull(StatusProto.fromThrowable(status.asException(emptyMetadata)));
+    assertEquals(statusFromThrowable.getCode(), status.getCode().value());
+    assertEquals(statusFromThrowable.getMessage(), status.getDescription());
   }
 
   @Test