impl(gax-httpjson): return empty ErrorDetails for garbage data instead of throwing RuntimeException

Author: westarle

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

@@ -101,6 +101,10 @@ static ErrorDetails parseErrorDetails(String errorJson) {
       }
 
       JsonElement errorElement = root.get("error");
+      if (!errorElement.isJsonObject()) {
+        return ErrorDetails.builder().build();
+      }
+
       Status.Builder statusBuilder = Status.newBuilder();
       JSON_PARSER.merge(errorElement.toString(), statusBuilder);
       Status status = statusBuilder.build();

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

@@ -111,14 +111,12 @@ void parseErrorDetails_noDetails() {
   @Test
   void parseErrorDetails_garbageInError() {
     String payload = "{\"error\": \"not-an-object\"}";
-    Assertions.assertThrows(
-        RuntimeException.class, () -> HttpJsonErrorParser.parseErrorDetails(payload));
+    assertThat(HttpJsonErrorParser.parseErrorDetails(payload).getErrorInfo()).isNull();
   }
 
   @Test
   void parseErrorDetails_arrayInError() {
     String payload = "{\"error\": []}";
-    Assertions.assertThrows(
-        RuntimeException.class, () -> HttpJsonErrorParser.parseErrorDetails(payload));
+    assertThat(HttpJsonErrorParser.parseErrorDetails(payload).getErrorInfo()).isNull();
   }
 }