CurrentObservationTest.java

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import static org.assertj.core.api.Assertions.assertThat;

@SuppressWarnings("NullAway")
class CurrentObservationTest {

    private final ObservationRegistry registry = ObservationRegistry.create();
    private final ExecutorService executor = Executors.newSingleThreadExecutor();

    @BeforeEach
    void setUp() {
        registry.observationConfig().observationHandler(new ObservationTextPublisher());
        registry.observationConfig().observationPredicate((name, context) -> !name.equals("b"));
    }

    @Test
    void currentTest() throws Exception {
        assertThat(registry.getCurrentObservation()).isNull();
        Observation.createNotStarted("a", registry).observeChecked(this::doA);
        assertThat(registry.getCurrentObservation()).isNull();
    }

    private void doA() throws Exception {
        assertThat(registry.getCurrentObservation().getContextView().getName()).isEqualTo("a");
        System.out.println("A...");
        Observation b = Observation.createNotStarted("b", registry).start();
        executor.submit(() -> {
            try (Observation.Scope ignored = b.openScope()) {
                assertThat(registry.getCurrentObservation()).isSameAs(b);
                doB();
                assertThat(registry.getCurrentObservation()).isSameAs(b);
            }
            assertThat(registry.getCurrentObservation()).isNull();
        }).get();
        assertThat(registry.getCurrentObservation().getContextView().getName()).isEqualTo("a");
    }

    private void doB() {
        System.out.println("B...");
        Observation.createNotStarted("c", registry).observe(this::doC);
    }

    private void doC() {
        assertThat(registry.getCurrentObservation().getContextView().getName()).isEqualTo("c");
        System.out.println("C! :)");
        assertThat(registry.getCurrentObservation().getContextView().getName()).isEqualTo("c");
    }

}