chore: add VisibleForTesting annotation (#11473)

chore: add VisibleForTesting annotation

Co-authored-by: brice.dutheil <brice.dutheil@datadoghq.com>

Author: bric3

communication/src/main/java/datadog/communication/serialization/FlushingBuffer.java

@@ -1,5 +1,6 @@
 package datadog.communication.serialization;
 
+import datadog.trace.api.internal.VisibleForTesting;
 import java.nio.ByteBuffer;
 
 public final class FlushingBuffer implements StreamingBuffer {
@@ -106,7 +107,7 @@ public void reset() {
     mark = 0;
   }
 
-  // for tests only
+  @VisibleForTesting
   int getMessageCount() {
     return messageCount;
   }

components/annotations/build.gradle.kts

@@ -0,0 +1 @@
+apply(from = "$rootDir/gradle/java.gradle")

components/annotations/src/main/java/datadog/trace/api/internal/VisibleForTesting.java

@@ -0,0 +1,10 @@
+package datadog.trace.api.internal;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.SOURCE)
+@Target({ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.METHOD, ElementType.TYPE})
+public @interface VisibleForTesting {}

components/environment/build.gradle.kts

@@ -5,6 +5,10 @@ plugins {
 
 apply(from = "$rootDir/gradle/java.gradle")
 
+dependencies {
+  compileOnly(project(":components:annotations"))
+}
+
 /*
  * Add an addition gradle configuration to be consumed by bootstrap only.
  * "datadog.trace." prefix is required to be excluded from Jacoco instrumentation.

components/environment/src/main/java/datadog/environment/JavaVirtualMachine.java

@@ -1,5 +1,6 @@
 package datadog.environment;
 
+import datadog.trace.api.internal.VisibleForTesting;
 import java.util.List;
 import java.util.Locale;
 import javax.annotation.Nullable;
@@ -212,7 +213,7 @@ public Runtime() {
           SystemProperties.get("java.vendor.version"));
     }
 
-    // Only visible for testing
+    @VisibleForTesting
     Runtime(String javaVer, String rtVer, String name, String vendor, String vendorVersion) {
       this.name = name == null ? "" : name;
       this.vendor = vendor == null ? "" : vendor;

components/environment/src/main/java/datadog/environment/JvmOptions.java

@@ -5,6 +5,7 @@
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 
+import datadog.trace.api.internal.VisibleForTesting;
 import de.thetaphi.forbiddenapis.SuppressForbidden;
 import java.io.BufferedReader;
 import java.io.IOException;
@@ -93,7 +94,7 @@ private List<String> findVmOptions() {
 
   // Be aware that when running a native image, the command line in /proc/self/cmdline is just the
   // executable
-  // Visible for testing
+  @VisibleForTesting
   List<String> findVmOptionsFromProcFs(String[] procfsCmdline) {
     // Create the list of VM options
     List<String> vmOptions = new ArrayList<>();

dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/InstrumentationErrors.java

@@ -1,5 +1,6 @@
 package datadog.trace.bootstrap;
 
+import datadog.trace.api.internal.VisibleForTesting;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.List;
@@ -30,7 +31,7 @@ public static Throwable recordError(Throwable error) {
     return error; // keep throwable at top of the stack
   }
 
-  // Visible for testing
+  @VisibleForTesting
   public static void resetErrors() {
     COUNTER.set(0);
     if (detailed) {

dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/WeakMapContextStore.java

@@ -1,5 +1,7 @@
 package datadog.trace.bootstrap;
 
+import datadog.trace.api.internal.VisibleForTesting;
+
 /**
  * Weak {@link ContextStore} that acts as a fall-back when field-injection isn't possible.
  *
@@ -85,7 +87,7 @@ public V remove(final K key) {
     return (V) map.remove(key);
   }
 
-  // Package reachable for testing
+  @VisibleForTesting
   int size() {
     return map.size();
   }

dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/blocking/BlockingActionHelper.java

@@ -6,6 +6,7 @@
 
 import datadog.appsec.api.blocking.BlockingContentType;
 import datadog.trace.api.Config;
+import datadog.trace.api.internal.VisibleForTesting;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
@@ -187,7 +188,7 @@ private static String nextMediaRange(String s, int[] pos, float[] quality) {
     return mediaRangeMatcher.group(1);
   }
 
-  // public for testing
+  @VisibleForTesting
   public static void reset(Config config) {
     TEMPLATE_HTML = null;
     TEMPLATE_JSON = null;

dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/dbm/SharedDBCommenter.java

@@ -4,6 +4,7 @@
 
 import datadog.trace.api.BaseHash;
 import datadog.trace.api.Config;
+import datadog.trace.api.internal.VisibleForTesting;
 import datadog.trace.bootstrap.instrumentation.api.AgentSpan;
 import datadog.trace.bootstrap.instrumentation.api.Tags;
 import java.io.UnsupportedEncodingException;
@@ -88,7 +89,7 @@ private static void ensureStaticPrefixComputed() {
     staticPrefixComputed = true;
   }
 
-  // @VisibleForTesting
+  @VisibleForTesting
   public static void resetStaticPrefixForTesting() {
     staticPrefixComputed = false;
   }