Rest-Client-Reactive: Custom `WebApplicationExceptions` not accessable by MP-Fault-Tolerance

Describe the bug

When using the retry mechanism of MP-Fault-Tolerance you usually do not want to retry on Status 400, i.e. bad requests. To achieve that, I annotated a method with @Retry(abortOn = BadRequestException.class) and converted 400 responses to a BadRequestException in a custom ResponseExceptionMapper<WebApplicationException>. That used to work with the old “Resteasy client”. Unfortunately, with Rest-Client-Reactive all WebApplicationExceptions are wrapped by corresponding ClientWebApplicationExceptions, so that the Retry is not able to distinguish between response codes.

See https://github.com/quarkusio/quarkus/issues/22777 for another issue regarding exception wrapping.

Expected behavior

Custom WebApplicationException types are passed through for interceptors like Retry

Actual behavior

All WebApplicationExceptions are converted to ClientWebApplicationExceptions

How to Reproduce?

@RegisterRestClient
@RegisterProvider(RestView.BadRequestExceptionMapper.class)
public interface RestView {
    @POST
    @Path("/test")
    @Retry(abortOn = BadRequestException.class)
    String test(String param);

    class BadRequestExceptionMapper implements ResponseExceptionMapper<WebApplicationException> {
        @Override
        public WebApplicationException toThrowable(Response response) {
            return new BadRequestException();
        }

        @Override
        public boolean handles(int status, MultivaluedMap<String, Object> headers) {
            return status == HttpStatus.SC_BAD_REQUEST;
        }
    }
}

Output of uname -a or ver

Microsoft Windows [Version 10.0.19042.1415]

Output of java -version

openjdk version “11.0.3” 2019-04-16 OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.3+7) OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.3+7, mixed mode)

GraalVM version (if different from Java)

No response

Quarkus version or git rev

2.6.1.Final

Build tool (ie. output of mvnw --version or gradlew --version)

Apache Maven 3.8.2 (ea98e05a04480131370aa0c110b8c54cf726c06f)

Additional information

No response

[Ladicek]

This is fixed in SmallRye Fault Tolerance 5.3.0, where in the non-compatible mode (which is on by default in Quarkus), exception cause chains are inspected.

[Ladicek]

There’s no release yet. There will be one soon, but it won’t make it into 2.7.