test: add util tests

inspectit-gepard-agent/src/main/java/rocks/inspectit/gepard/agent/instrumentation/hook/action/util/SpanUtil.java

@@ -34,8 +34,8 @@ private SpanUtil() {}
    * prevent span duplicates. For example, we would like to create a span for a method, which is
    * already recorded by OpenTelemetry. In this case, we should not create a new span.
    *
-   * @param spanName the name of the span with the format 'simple-class-name.method-name', for
-   *     instance 'SpanUtil.spanAlreadyExists'
+   * @param spanName the name of the span with the format 'SimpleClassName.methodName', for instance
+   *     'SpanUtil.spanAlreadyExists'
    * @return true, if the current span uses the provided span name
    */
   public static boolean spanAlreadyExists(String spanName)

inspectit-gepard-agent/src/test/java/rocks/inspectit/gepard/agent/instrumentation/hook/action/util/SpanUtilTest.java

@@ -0,0 +1,66 @@
+/* (C) 2024 */
+package rocks.inspectit.gepard.agent.instrumentation.hook.action.util;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.context.Scope;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class SpanUtilTest {
+
+  private Tracer tracer;
+
+  private final String spanName = "SpanUtilTest.method";
+
+  @BeforeEach
+  void beforeEach() {
+    OpenTelemetry openTelemetry = OpenTelemetrySdk.builder().buildAndRegisterGlobal();
+    tracer = openTelemetry.getTracer("inspectit-gepard");
+  }
+
+  @AfterEach
+  void afterEach() {
+    GlobalOpenTelemetry.resetForTest();
+  }
+
+  @Test
+  void shouldReturnTrueWhenSpanExists() throws Exception {
+    Span span = tracer.spanBuilder(spanName).startSpan();
+    Scope scope = span.makeCurrent();
+
+    boolean exists = SpanUtil.spanAlreadyExists(spanName);
+
+    assertTrue(exists);
+
+    scope.close();
+    span.end();
+  }
+
+  @Test
+  void shouldReturnFalseWhenNoSpanExists() throws Exception {
+    boolean exists = SpanUtil.spanAlreadyExists(spanName);
+
+    assertFalse(exists);
+  }
+
+  @Test
+  void shouldReturnFalseWhenOtherSpanExists() throws Exception {
+    Span span = tracer.spanBuilder("dummy").startSpan();
+    Scope scope = span.makeCurrent();
+
+    boolean exists = SpanUtil.spanAlreadyExists(spanName);
+
+    assertFalse(exists);
+
+    scope.close();
+    span.end();
+  }
+}