content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.javaagent.instrumentation.finatra;
  
  import static net.bytebuddy.matcher.ElementMatchers.isMethod;
  import static net.bytebuddy.matcher.ElementMatchers.named;
  import static net.bytebuddy.matcher.ElementMatchers.returns;
  import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
  
  import com.twitter.finagle.http.Response;
  import io.opentelemetry.instrumentation.api.util.VirtualField;
  import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
  import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;
  import net.bytebuddy.asm.Advice;
  import net.bytebuddy.description.type.TypeDescription;
  import net.bytebuddy.matcher.ElementMatcher;
  
  public class FinatraExceptionManagerInstrumentation implements TypeInstrumentation {
    @Override
    public ElementMatcher<TypeDescription> typeMatcher() {
      return named("com.twitter.finatra.http.exceptions.ExceptionManager");
    }
  
    @Override
    public void transform(TypeTransformer transformer) {
      transformer.applyAdviceToMethod(
          isMethod()
              .and(named("toResponse"))
              .and(takesArgument(1, Throwable.class))
              .and(returns(named("com.twitter.finagle.http.Response"))),
          this.getClass().getName() + "$HandleExceptionAdvice");
    }
  
    @SuppressWarnings("unused")
    public static class HandleExceptionAdvice {
  
      @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
      public static void handleException(
          @Advice.Return Response response, @Advice.Argument(1) Throwable throwable) {
  
        if (throwable == null) {
          return;
        }
  
        VirtualField<Response, Throwable> virtualField =
            VirtualField.find(Response.class, Throwable.class);
        virtualField.set(response, throwable);
      }
    }
  }
  