feat: classpath cache

Author: daniel-mohedano

dd-java-agent/instrumentation/karate/karate-2.0/src/main/java21/datadog/trace/instrumentation/karate2/KarateUtils.java

@@ -21,6 +21,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
 
 public abstract class KarateUtils {
 
@@ -36,20 +37,24 @@ private KarateUtils() {}
           LibraryCapability.TIA,
           LibraryCapability.DISABLED);
 
+  private static final ConcurrentHashMap<URI, String> CLASSPATH_NAME_CACHE =
+      new ConcurrentHashMap<>();
+
   public static Feature getFeature(FeatureRuntime featureRuntime) {
     return featureRuntime.getFeature();
   }
 
   /**
-   * Karate v2's {@code Feature.getNameForReport()} composes the identifier from {@code
-   * Resource.getRelativePath()}, which v2 computes by relativizing the resolved {@code file://}
-   * URL against the JVM's working directory — build-relative locally, absolute on CI runners.
-   * Karate v1 sidestepped this by tracking the classpath root via ClassGraph, so its identifier
-   * ({@code "[org/example/test_succeed] test succeed"}) is stable across environments.
+   * Produces the karate-1.0-compatible suite identifier {@code "[<classpath-relative-path>]
+   * <name>"} (e.g. {@code "[org/example/test_succeed] test succeed"}).
+   *
+   * <p>We can't use v2's {@code Feature.getNameForReport()} directly: it derives the path from
+   * {@code Resource.getRelativePath()}, which v2 relativizes against the JVM working directory and
+   * falls back to the absolute path when the file is outside it.
    *
-   * <p>We recover the same classpath-relative form here by asking the classloader to resolve
-   * progressively longer suffixes of the feature file's path — the first suffix whose {@code
-   * ClassLoader.getResource(...)} returns the same URL is the classpath-relative name.
+   * <p>We recover that form by asking the classloader to resolve progressively longer suffixes of
+   * the feature's path; the shortest suffix that resolves back to the same file is the
+   * classpath-relative name. Falls back to the bare filename if nothing resolves.
    */
   public static String getFeatureNameForReport(Feature feature) {
     if (feature == null) {
@@ -68,6 +73,10 @@ private static String resolveClasspathRelativeName(Feature feature) {
     if (uri == null) {
       return feature.getName() != null ? feature.getName() : "";
     }
+    return CLASSPATH_NAME_CACHE.computeIfAbsent(uri, KarateUtils::computeClasspathRelativeName);
+  }
+
+  private static String computeClasspathRelativeName(URI uri) {
     Path path;
     try {
       path = Paths.get(uri);