Fix Kotlin Debug source mapping (#11803)

Fix Kotlin Debug source mapping

KotlinDebug stratum in SMAP is not always emitted
if not present make one empty and avoid throwing exception

fix unit tests

Co-authored-by: devflow.devflow-routing-intake <devflow.devflow-routing-intake@kubernetes.us1.ddbuild.io>

Author: jpbempel

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/symbol/SourceRemapper.java

@@ -22,7 +22,7 @@ static SourceRemapper getSourceRemapper(String sourceFile, SourceMap sourceMap)
         }
         StratumExt stratumDebug = sourceMap.getStratum("KotlinDebug");
         if (stratumDebug == null) {
-          throw new IllegalArgumentException("No stratumDebug found for KotlinDebug");
+          stratumDebug = new StratumExt("KotlinDebug");
         }
         return new KotlinSourceRemapper(stratumMain, stratumDebug);
       default:

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/symbol/SourceRemapperTest.java

@@ -38,10 +38,7 @@ public void noKotlinDebug() {
     StratumExt stratumMainMock = mock(StratumExt.class);
     when(sourceMapMock.getStratum(eq("Kotlin"))).thenReturn(stratumMainMock);
     when(sourceMapMock.getStratum(eq("KotlinDebug"))).thenReturn(null);
-    IllegalArgumentException illegalArgumentException =
-        assertThrows(
-            IllegalArgumentException.class,
-            () -> SourceRemapper.getSourceRemapper("foo.kt", sourceMapMock));
-    assertEquals("No stratumDebug found for KotlinDebug", illegalArgumentException.getMessage());
+    SourceRemapper sourceRemapper = SourceRemapper.getSourceRemapper("foo.kt", sourceMapMock);
+    assertNotNull(sourceRemapper);
   }
 }

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/symbol/SymbolExtractionTransformerTest.java

@@ -995,13 +995,13 @@ public void symbolExtraction16() throws IOException, URISyntaxException {
           KotlinHelper.compileAndLoad(CLASS_NAME, resource.getFile(), filesToDelete);
       Object companion = Reflect.onClass(testClass).get("Companion");
       int result = Reflect.on(companion).call("main", "").get();
-      assertEquals(48, result);
+      assertEquals(73, result);
     } finally {
       filesToDelete.forEach(File::delete);
     }
-    assertEquals(2, symbolSinkMock.jarScopes.size());
+    assertEquals(4, symbolSinkMock.jarScopes.size());
     Scope classScope = symbolSinkMock.jarScopes.get(0).getScopes().get(0);
-    assertScope(classScope, ScopeType.CLASS, CLASS_NAME, 6, 23, SOURCE_FILE, 5, 1);
+    assertScope(classScope, ScopeType.CLASS, CLASS_NAME, 6, 28, SOURCE_FILE, 6, 1);
     assertLangSpecifics(
         classScope.getLanguageSpecifics(),
         asList("public", "final"),
@@ -1026,12 +1026,15 @@ public void symbolExtraction16() throws IOException, URISyntaxException {
     Scope f3MethodScope = classScope.getScopes().get(3);
     assertScope(f3MethodScope, ScopeType.METHOD, "f3", 21, 23, SOURCE_FILE, 1, 1);
     assertLineRanges(f3MethodScope, "21-23");
+    Scope f4MethodScope = classScope.getScopes().get(4);
+    assertScope(f4MethodScope, ScopeType.METHOD, "f4", 27, 28, SOURCE_FILE, 1, 1);
+    assertLineRanges(f4MethodScope, "27-28");
     assertScope(
-        classScope.getScopes().get(4), ScopeType.METHOD, "<clinit>", 0, 0, SOURCE_FILE, 0, 0);
+        classScope.getScopes().get(5), ScopeType.METHOD, "<clinit>", 0, 0, SOURCE_FILE, 0, 0);
 
     Scope companionClassScope = symbolSinkMock.jarScopes.get(1).getScopes().get(0);
     assertScope(
-        companionClassScope, ScopeType.CLASS, CLASS_NAME + "$Companion", 28, 29, SOURCE_FILE, 3, 0);
+        companionClassScope, ScopeType.CLASS, CLASS_NAME + "$Companion", 33, 34, SOURCE_FILE, 3, 0);
     assertLangSpecifics(
         classScope.getLanguageSpecifics(),
         asList("public", "final"),
@@ -1049,8 +1052,8 @@ public void symbolExtraction16() throws IOException, URISyntaxException {
         0,
         0);
     Scope mainMethodScope = companionClassScope.getScopes().get(1);
-    assertScope(mainMethodScope, ScopeType.METHOD, "main", 28, 29, SOURCE_FILE, 1, 1);
-    assertLineRanges(mainMethodScope, "28-29");
+    assertScope(mainMethodScope, ScopeType.METHOD, "main", 33, 34, SOURCE_FILE, 1, 1);
+    assertLineRanges(mainMethodScope, "33-34");
   }
 
   @Test

dd-java-agent/agent-debugger/src/test/resources/com/datadog/debugger/symboltest/SymbolExtraction16.kt

@@ -23,10 +23,17 @@ class SymbolExtraction16 {
     return value
   }
 
+  fun f4(value: Int): Int {
+    val set = setOf(Person("john", "doe"), Person("agent", "smith"))
+    return set.groupingBy { it.firstName }.eachCount().toMutableMap().size
+  }
+
   companion object {
     fun main(arg: String): Int {
       val c = SymbolExtraction16()
-      return c.f1(31) + c.f2(17)
+      return c.f1(31) + c.f2(17) + c.f3(23) + c.f4(0)
     }
   }
 }
+
+data class Person(val firstName: String, val lastName: String)