Migrate dd-trace-core groovy files to java part 3 (#11085)

Migrate dd-trace-core groovy files to java part 3

we migrate 3 small tests:
 - BlackholeSpanTest
 - LongRunningTracesTrackerTest
 - TraceCorrelationTest
using new SpanConfigExtension for injecting config

replace injectSysConfig by @WithConfig

spotless

replace tabletest by valuesource for single param

Co-authored-by: jean-philippe.bempel <jean-philippe.bempel@datadoghq.com>

Author: jpbempel

.claude/skills/migrate-groovy-to-java/SKILL.md

@@ -20,6 +20,7 @@ When converting Groovy code to Java code, make sure that:
 - `@TableTest` and `@MethodSource` may be combined on the same `@ParameterizedTest` when most cases are tabular but a few cases require programmatic setup.
 - In combined mode, keep table-friendly cases in `@TableTest`, and put only non-tabular/complex cases in `@MethodSource`.
 - If `@TableTest` is not viable for the test at all, use `@MethodSource` only.
+- If `@TableTest` was successfully used and if the `@ParameterizedTest` is not used to specify the test name, `@ParameterizedTest` can then be removed as `@TableTest` replace it fully.
 - For `@MethodSource`, name the arguments method `<testMethodName>Arguments` (camelCase, e.g. `testMethodArguments`) and return `Stream<Arguments>` using `Stream.of(...)` and `arguments(...)` with static import.
 - Ensure parameterized test names are human-readable (i.e. no hashcodes); instead add a description string as the first `Arguments.arguments(...)` value or index the test case
 - When converting tuples, create a light dedicated structure instead to keep the typing system

dd-trace-core/build.gradle

@@ -107,6 +107,7 @@ dependencies {
   testImplementation group: 'com.amazonaws', name: 'aws-lambda-java-events', version:'3.11.0'
   testImplementation group: 'com.google.protobuf', name: 'protobuf-java', version: '3.14.0'
   testImplementation libs.testcontainers
+  testImplementation project(':utils:junit-utils')
 
   traceAgentTestImplementation libs.testcontainers
 }

dd-trace-core/src/main/java/datadog/trace/core/LongRunningTracesTracker.java

@@ -139,4 +139,14 @@ private void flushStats() {
     write = 0;
     expired = 0;
   }
+
+  // @VisibleForTesting
+  int trackedCount() {
+    return traceArray.size();
+  }
+
+  // @VisibleForTesting
+  int getDropped() {
+    return dropped;
+  }
 }

dd-trace-core/src/main/java/datadog/trace/core/PendingTrace.java

@@ -223,6 +223,16 @@ boolean compareAndSetLongRunningState(int expected, int newState) {
     return LONG_RUNNING_STATE.compareAndSet(this, expected, newState);
   }
 
+  // @VisibleForTesting
+  int getLongRunningTrackedState() {
+    return longRunningTrackedState;
+  }
+
+  // @VisibleForTesting
+  void setLongRunningTrackedState(int state) {
+    LONG_RUNNING_STATE.set(this, state);
+  }
+
   boolean empty() {
     return 0 >= COMPLETED_SPAN_COUNT.get(this) + PENDING_REFERENCE_COUNT.get(this);
   }

dd-trace-core/src/main/java/datadog/trace/core/PendingTraceBuffer.java

@@ -54,7 +54,7 @@ public interface Element {
     boolean writeOnBufferFull();
   }
 
-  private static class DelayingPendingTraceBuffer extends PendingTraceBuffer {
+  static class DelayingPendingTraceBuffer extends PendingTraceBuffer {
     private static final long FORCE_SEND_DELAY_MS = TimeUnit.SECONDS.toMillis(5);
     private static final long SEND_DELAY_NS = TimeUnit.MILLISECONDS.toNanos(500);
     private static final long SLEEP_TIME_MS = 100;
@@ -303,6 +303,11 @@ public DelayingPendingTraceBuffer(
                   config, bufferSize, sharedCommunicationObjects, healthMetrics)
               : null;
     }
+
+    // @VisibleForTesting
+    LongRunningTracesTracker getRunningTracesTracker() {
+      return runningTracesTracker;
+    }
   }
 
   static class DiscardingPendingTraceBuffer extends PendingTraceBuffer {