Log a warning when GlobalOpenTelemetry#resetForTest() is called (#6212)

instrumentation/opentelemetry-api/opentelemetry-api-1.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/opentelemetryapi/OpenTelemetryInstrumentation.java

@@ -45,6 +45,9 @@ public void transform(TypeTransformer transformer) {
  .and(takesArguments(1))
  .and(takesArgument(0, named("application.io.opentelemetry.api.OpenTelemetry"))),
  OpenTelemetryInstrumentation.class.getName() + "$SetAdvice");
+ transformer.applyAdviceToMethod(
+ isMethod().and(isStatic()).and(named("resetForTest")).and(takesArguments(0)),
+ OpenTelemetryInstrumentation.class.getName() + "$ResetForTestAdvice");
  }
 
  @SuppressWarnings("unused")
@@ -77,4 +80,19 @@ public static void onEnter() {
  new Throwable());
  }
  }
+
+ @SuppressWarnings("unused")
+ public static class ResetForTestAdvice {
+
+ @Advice.OnMethodEnter(suppress = Throwable.class)
+ public static void onEnter() {
+ Logger.getLogger(application.io.opentelemetry.api.GlobalOpenTelemetry.class.getName())
+ .log(
+ WARNING,
+ "You are currently using the OpenTelemetry Instrumentation Java Agent;"
+ + " all GlobalOpenTelemetry.resetForTest calls are ignored - the agent provides"
+ + " the global OpenTelemetry object used by your application.",
+ new Throwable());
+ }
+ }
 }