can´t mock brave.Tracer

[dotarsoyak]

Hi

I´m trying to mock brave.Tracer. to get Tracer.currenSpan(), but I can´t get it, here is my code.

I´m usign:

• io.zipkin.brave:5.13.9
• spring-cloud-sleuth-zipkin:3.1.3

could you give me some advice?

my test method

import brave.Span;
import brave.Tracer;
import brave.Tracing;

@ExtendedWith(SpringExtension.class)
@ActiveProfiles("test")
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM.PORT,
classes = {Main.class, TestConfig.class})
public class TestingClass{
  
  @Autowired
  private Tracer tracer;

  @Test
  public void must_return_currentSpan() throws Exception {
    brave.Span span = Tracing.newBuilder().build().tracer().nextSpan().name("span").start();

    doReturn(span).when(tracer).currentSpan();

    mvc.perform(get("the url"));  //this is only contextual, an example to avoid write all code.
  }
}

the class to test

import brave.Span;

@Service
@RequiredArgsConstructor
public class TheClass {
  private final Tracer tracer;

  public Span generateSpan() {
    return tracer.currentSpan();
  }

}

In some point after execute the test method, I get this error

java.lang.NullPointerException: Cannot invoke "brave.Tracer$SpanInScope.close()" because "this.delegate" is null 
at org.springframework.cloud.sleuth.brave.bridge.BraveSpanInScope.close(BraveTracer.java:153)