fix(gax-httpjson): gracefully handle error details with unrecognized types

Author: whowes

java-showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITErrorDetails.java

@@ -187,16 +187,12 @@ void testHttpJson_failEchoWithDetails() throws Exception {
         assertThrows(ApiException.class, () -> httpjsonClient.failEchoWithDetails(request));
     assertThat(exception.getStatusCode().getCode()).isEqualTo(StatusCode.Code.ABORTED);
 
-    // GAX HTTP/JSON parser limitation: Because the response contains a custom/unregistered type
-    // (PoetryError) in the Any details list, HttpJsonErrorParser fails to parse the status payload,
-    // resulting in empty ErrorDetails (where getErrorInfo() returns null).
-    // Note: Standard Google Cloud services follow AIP-193 error details (ErrorInfo, RetryInfo,
-    // etc.)
-    // and do not use custom error payload types like PoetryError.
+    // The response contains a custom/unregistered type (PoetryError) in the Any details list.
+    // HttpJsonErrorParser filters out unrecognized details so standard ones (e.g. ErrorInfo) are
+    // still parsed.
     ErrorDetails errorDetails = exception.getErrorDetails();
-    if (errorDetails != null) {
-      assertThat(errorDetails.getErrorInfo()).isNull();
-    }
+    assertThat(errorDetails).isNotNull();
+    assertThat(errorDetails.getErrorInfo()).isNotNull();
 
     // Workaround REST limitation: Parse the raw HTTP JSON error response manually using a custom
     // TypeRegistry that registers standard types plus the showcase-specific PoetryError type.

sdk-platform-java/gax-java/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonErrorParser.java

@@ -32,6 +32,7 @@
 
 import com.google.api.core.InternalApi;
 import com.google.api.gax.rpc.ErrorDetails;
+import com.google.common.collect.Iterables;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
@@ -112,13 +113,34 @@ static Status parseStatus(String errorJson) {
       return Status.getDefaultInstance();
     }
 
+    JsonObject errorObject = errorElement.getAsJsonObject();
+    JsonElement detailsElement = errorObject.get("details");
+    if (detailsElement != null && detailsElement.isJsonArray()) {
+      Iterables.removeIf(detailsElement.getAsJsonArray(), detail -> !isRecognizedDetail(detail));
+    }
+
     Status.Builder statusBuilder = Status.newBuilder();
     try {
-      JSON_PARSER.merge(errorElement.toString(), statusBuilder);
+      JSON_PARSER.merge(errorObject.toString(), statusBuilder);
     } catch (InvalidProtocolBufferException e) {
       return Status.getDefaultInstance();
     }
 
     return statusBuilder.build();
   }
+
+  private static boolean isRecognizedDetail(JsonElement detail) {
+    if (!detail.isJsonObject()) {
+      return false;
+    }
+    JsonElement typeElement = detail.getAsJsonObject().get("@type");
+    if (typeElement == null || !typeElement.isJsonPrimitive()) {
+      return false;
+    }
+    try {
+      return STANDARD_ERROR_TYPES.getDescriptorForTypeUrl(typeElement.getAsString()) != null;
+    } catch (InvalidProtocolBufferException e) {
+      return false;
+    }
+  }
 }

sdk-platform-java/gax-java/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonApiExceptionFactoryTest.java

@@ -148,4 +148,43 @@ void testCreate_withoutErrorDetails() {
     assertThat(apiException.getErrorDetails()).isNotNull();
     assertThat(apiException.getErrorDetails().getErrorInfo()).isNull();
   }
+
+  @Test
+  void testCreate_unrecognizedProtoInDetails_preservesMessageAndOtherDetails() {
+    String payload =
+        "{\n"
+            + "  \"error\": {\n"
+            + "    \"code\": 400,\n"
+            + "    \"message\": \"Request contains an invalid argument.\",\n"
+            + "    \"details\": [\n"
+            + "      {\n"
+            + "        \"@type\": \"type.googleapis.com/custom.UnrecognizedDetail\",\n"
+            + "        \"detailMessage\": \"'123-invalid' is not a valid customer ID.\"\n"
+            + "      },\n"
+            + "      {\n"
+            + "        \"@type\": \"type.googleapis.com/google.rpc.ErrorInfo\",\n"
+            + "        \"reason\": \"INVALID_CUSTOMER_ID\",\n"
+            + "        \"domain\": \"googleapis.com\"\n"
+            + "      }\n"
+            + "    ]\n"
+            + "  }\n"
+            + "}";
+
+    // HttpResponseException(HttpResponse) populates message with the status line + content.
+    HttpResponseException exception =
+        new HttpResponseException.Builder(400, "Bad Request", new HttpHeaders())
+            .setContent(payload)
+            .setMessage("400 Bad Request\n" + payload)
+            .build();
+
+    HttpJsonApiExceptionFactory factory =
+        new HttpJsonApiExceptionFactory(ImmutableSet.of(Code.UNAVAILABLE));
+    ApiException apiException = factory.create(exception);
+
+    assertThat(apiException.getStatusCode().getCode()).isEqualTo(Code.INVALID_ARGUMENT);
+    assertThat(apiException.getMessage()).contains("Request contains an invalid argument.");
+    assertThat(apiException.getReason()).isEqualTo("INVALID_CUSTOMER_ID");
+    assertThat(((HttpResponseException) apiException.getCause()).getContent())
+        .contains("'123-invalid' is not a valid customer ID.");
+  }
 }

sdk-platform-java/gax-java/gax-httpjson/src/test/java/com/google/api/gax/httpjson/HttpJsonErrorParserTest.java

@@ -135,4 +135,40 @@ void parseStatus_arrayInError() {
     assertThat(HttpJsonErrorParser.parseStatus(payload))
         .isEqualTo(com.google.rpc.Status.getDefaultInstance());
   }
+
+  @Test
+  void parseStatus_unrecognizedOrMalformedDetails_ignoresAndPreservesOthers() {
+    String payload =
+        "{\n"
+            + "  \"error\": {\n"
+            + "    \"code\": 400,\n"
+            + "    \"message\": \"Invalid request payload.\",\n"
+            + "    \"details\": [\n"
+            + "      \"not-an-object\",\n"
+            + "      {\n"
+            + "        \"customField\": \"missingAtType\"\n"
+            + "      },\n"
+            + "      {\n"
+            + "        \"@type\": \"malformed-type-url-without-slash\"\n"
+            + "      },\n"
+            + "      {\n"
+            + "        \"@type\": \"type.googleapis.com/custom.UnrecognizedErrorDetail\",\n"
+            + "        \"customField\": \"customValue\"\n"
+            + "      },\n"
+            + "      {\n"
+            + "        \"@type\": \"type.googleapis.com/google.rpc.RetryInfo\"\n"
+            + "      }\n"
+            + "    ]\n"
+            + "  }\n"
+            + "}";
+
+    com.google.rpc.Status status = HttpJsonErrorParser.parseStatus(payload);
+    assertThat(status.getCode()).isEqualTo(400);
+    assertThat(status.getMessage()).isEqualTo("Invalid request payload.");
+    assertThat(status.getDetailsCount()).isEqualTo(1);
+
+    ErrorDetails errorDetails =
+        ErrorDetails.builder().setRawErrorMessages(status.getDetailsList()).build();
+    assertThat(errorDetails.getRetryInfo()).isNotNull();
+  }
 }