SONARJAVA-5978 Support Compact Source Files (#5397)

tomasz-tylenda-sonarsource · dorian-burihabwa-sonarsource · web-flow · commit f3052282779f · 2026-02-02T16:30:47.000Z
Co-authored-by: Dorian Burihabwa &lt;75226315+dorian-burihabwa-sonarsource@users.noreply.github.com&gt;
diff --git a/java-checks-test-sources/default/src/main/java/checks/HiddenFieldCheckCompactSample.java b/java-checks-test-sources/default/src/main/java/checks/HiddenFieldCheckCompactSample.java
@@ -0,0 +1,11 @@
+void main() {
+  int a = 5;
+  int x = 10; // Noncompliant {{Rename "x" which hides the field declared at line 11.}}
+//    ^
+  float b = 3.14f;
+  System.out.println(a);
+  System.out.println(x);
+  System.out.println(b);
+}
+
+int x = 20;
diff --git a/java-checks-test-sources/default/src/main/java/checks/IndentationCheck_compactSource.java b/java-checks-test-sources/default/src/main/java/checks/IndentationCheck_compactSource.java
@@ -0,0 +1,11 @@
+// SONARJAVA-6028: FPs ahead. Only the line with "Too much." should be noncompliant.
+
+void main() { // Noncompliant
+  System.out.println("Just right."); // Noncompliant
+  if (true) {
+        System.out.println("Too much."); // Noncompliant
+  }
+}
+
+class MyClass { // Noncompliant
+}
diff --git a/java-checks/src/main/java/org/sonar/java/checks/HiddenFieldCheck.java b/java-checks/src/main/java/org/sonar/java/checks/HiddenFieldCheck.java
@@ -59,6 +59,7 @@ public List<Tree.Kind> nodesToVisit() {
         Tree.Kind.INTERFACE,
         Tree.Kind.ANNOTATION_TYPE,
         Tree.Kind.RECORD,
+        Tree.Kind.IMPLICIT_CLASS,
         Tree.Kind.VARIABLE,
         Tree.Kind.METHOD,
         Tree.Kind.CONSTRUCTOR,
@@ -130,7 +131,14 @@ private static boolean isInStaticInnerClass(VariableTree hiddenVariable, Variabl
   }
 
   private static boolean isClassTree(Tree tree) {
-    return tree.is(Tree.Kind.CLASS, Tree.Kind.ENUM, Tree.Kind.INTERFACE, Tree.Kind.ANNOTATION_TYPE, Tree.Kind.RECORD);
+    return tree.is(
+      Tree.Kind.CLASS,
+      Tree.Kind.ENUM,
+      Tree.Kind.INTERFACE,
+      Tree.Kind.ANNOTATION_TYPE,
+      Tree.Kind.RECORD,
+      Tree.Kind.IMPLICIT_CLASS
+    );
   }
 
   @Override
diff --git a/java-checks/src/main/java/org/sonar/java/checks/IndentationCheck.java b/java-checks/src/main/java/org/sonar/java/checks/IndentationCheck.java
@@ -72,13 +72,13 @@ public void scanFile(JavaFileScannerContext context) {
 
   @Override
   public void visitClass(ClassTree tree) {
-    // Exclude anonymous classes
-    boolean isAnonymous = tree.simpleName() == null;
-    if (!isAnonymous) {
+    // Exclude anonymous classes other than implicit classed of compact source files.
+    boolean isExcluded = tree.simpleName() == null && !tree.is(Kind.IMPLICIT_CLASS);
+    if (!isExcluded) {
       checkIndentation(Collections.singletonList(tree));
     }
     int previousLevel = expectedLevel;
-    if (isAnonymous) {
+    if (isExcluded) {
       excludeIssueAtLine = LineUtils.startLine(tree.openBraceToken());
       expectedLevel = Position.startOf(tree.closeBraceToken()).columnOffset();
     }
diff --git a/java-checks/src/test/java/org/sonar/java/checks/HiddenFieldCheckTest.java b/java-checks/src/test/java/org/sonar/java/checks/HiddenFieldCheckTest.java
@@ -40,4 +40,11 @@ void test_records() {
       .verifyIssues();
   }
 
+  @Test
+  void test_compact_source() {
+    CheckVerifier.newVerifier()
+      .onFile(mainCodeSourcesPath("checks/HiddenFieldCheckCompactSample.java"))
+      .withCheck(new HiddenFieldCheck())
+      .verifyIssues();
+  }
 }
diff --git a/java-checks/src/test/java/org/sonar/java/checks/IndentationCheckTest.java b/java-checks/src/test/java/org/sonar/java/checks/IndentationCheckTest.java
@@ -57,4 +57,12 @@ void tolerates_line_breaking_control_characters() {
       .withCheck(new IndentationCheck())
       .verifyNoIssues();
   }
+
+  @Test
+  void compact_source_file() {
+    CheckVerifier.newVerifier()
+      .onFile(mainCodeSourcesPath("checks/IndentationCheck_compactSource.java"))
+      .withCheck(new IndentationCheck())
+      .verifyIssues();
+  }
 }
diff --git a/java-frontend/src/main/java/org/sonar/java/JavaFilesCache.java b/java-frontend/src/main/java/org/sonar/java/JavaFilesCache.java
@@ -50,6 +50,8 @@ public void scanFile(JavaFileScannerContext context) {
     currentClassKey.clear();
     parent.clear();
     anonymousInnerClassCounter.clear();
+    // 0 stored on the top will be used for implicit anonymous classes in compact source files.
+    anonymousInnerClassCounter.push(0);
     scan(tree);
   }
 
@@ -77,9 +79,10 @@ private String getClassKey(String className) {
       key = currentPackage + "/" + className;
     }
     if ("".equals(className) || (parent.peek() != null && parent.peek().is(Tree.Kind.METHOD))) {
-      // inner class declared within method
+      // inner class declared within method or implicitly declared class in a compact source file
       int count = anonymousInnerClassCounter.pop() + 1;
-      key = currentClassKey.peek() + "$" + count + className;
+      String prefix = currentClassKey.isEmpty() ? "" : currentClassKey.peek();
+      key = prefix + "$" + count + className;
       anonymousInnerClassCounter.push(count);
     } else if (currentClassKey.peek() != null) {
       key = currentClassKey.peek() + "$" + className;
diff --git a/java-frontend/src/main/java/org/sonar/java/Measurer.java b/java-frontend/src/main/java/org/sonar/java/Measurer.java
@@ -17,6 +17,7 @@
 package org.sonar.java;
 
 import java.io.Serializable;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Deque;
 import java.util.LinkedList;
@@ -38,6 +39,15 @@
 
 public class Measurer extends SubscriptionVisitor {
 
+  private static final Tree.Kind[] CLASS_KINDS = new Tree.Kind[]{
+    Tree.Kind.CLASS,
+    Tree.Kind.INTERFACE,
+    Tree.Kind.ENUM,
+    Tree.Kind.ANNOTATION_TYPE,
+    Tree.Kind.RECORD,
+    Tree.Kind.IMPLICIT_CLASS
+  };
+
   private final SensorContext sensorContext;
   private final NoSonarFilter noSonarFilter;
   private InputFile sonarFile;
@@ -61,9 +71,13 @@ public void scanFile(JavaFileScannerContext context) {
 
   @Override
   public List<Tree.Kind> nodesToVisit() {
-    return Arrays.asList(Tree.Kind.CLASS, Tree.Kind.INTERFACE, Tree.Kind.ENUM, Tree.Kind.ANNOTATION_TYPE, Tree.Kind.RECORD,
-        Tree.Kind.NEW_CLASS, Tree.Kind.ENUM_CONSTANT,
-        Tree.Kind.METHOD, Tree.Kind.CONSTRUCTOR);
+    List<Tree.Kind> nodes = new ArrayList<>(Arrays.asList(CLASS_KINDS));
+    nodes.addAll(Arrays.asList(
+      Tree.Kind.NEW_CLASS,
+      Tree.Kind.ENUM_CONSTANT,
+      Tree.Kind.METHOD,
+      Tree.Kind.CONSTRUCTOR));
+    return nodes;
   }
 
 
@@ -120,7 +134,7 @@ public void leaveNode(Tree tree) {
   }
 
   private static boolean isClassTree(Tree tree) {
-    return tree.is(Tree.Kind.CLASS, Tree.Kind.INTERFACE, Tree.Kind.ENUM, Tree.Kind.ANNOTATION_TYPE, Tree.Kind.RECORD);
+    return tree.is(CLASS_KINDS);
   }
 
   private <T extends Serializable> void saveMetricOnFile(Metric<T> metric, T value) {
diff --git a/java-frontend/src/main/java/org/sonar/java/ast/visitors/PublicApiChecker.java b/java-frontend/src/main/java/org/sonar/java/ast/visitors/PublicApiChecker.java
@@ -43,7 +43,8 @@ private PublicApiChecker() {
     Tree.Kind.INTERFACE,
     Tree.Kind.ENUM,
     Tree.Kind.ANNOTATION_TYPE,
-    Tree.Kind.RECORD
+    Tree.Kind.RECORD,
+    Tree.Kind.IMPLICIT_CLASS
   };
 
   private static final Tree.Kind[] METHOD_KINDS = {
diff --git a/java-frontend/src/main/java/org/sonar/java/model/JParser.java b/java-frontend/src/main/java/org/sonar/java/model/JParser.java
@@ -769,7 +769,27 @@ private ModuleDirectiveTree convertModuleDirective(ModuleDirective node) {
     }
   }
 
+  /** Converts implicitly declared unnamed class at the top level of a compact compilation unit. */
+  private ClassTreeImpl convertUnnamedClassDeclaration(AbstractTypeDeclaration e) {
+    List<Tree> members = new ArrayList<>();
+
+    for (Object o : e.bodyDeclarations()) {
+      processBodyDeclaration((BodyDeclaration) o, members);
+    }
+
+    ClassTreeImpl t = new ClassTreeImpl(Tree.Kind.IMPLICIT_CLASS, null, members, null);
+
+    t.typeBinding = e.resolveBinding();
+    declaration(t.typeBinding, t);
+
+    return t;
+  }
+
   private ClassTreeImpl convertTypeDeclaration(AbstractTypeDeclaration e) {
+    if (e.getNodeType() == ASTNode.UNNAMED_CLASS) {
+      return convertUnnamedClassDeclaration(e);
+    }
+
     List<Tree> members = new ArrayList<>();
 
     int leftBraceTokenIndex = findLeftBraceTokenIndex(e);
@@ -932,7 +952,7 @@ private static List<?> superInterfaceTypes(AbstractTypeDeclaration e) {
         return ((EnumDeclaration) e).superInterfaceTypes();
       case ASTNode.RECORD_DECLARATION:
         return ((RecordDeclaration) e).superInterfaceTypes();
-      case ASTNode.ANNOTATION_TYPE_DECLARATION:
+      case ASTNode.ANNOTATION_TYPE_DECLARATION, ASTNode.UNNAMED_CLASS:
         return Collections.emptyList();
       default:
         throw new IllegalStateException(ASTNode.nodeClassForType(e.getNodeType()).toString());
@@ -1021,7 +1041,8 @@ private void processBodyDeclaration(BodyDeclaration node, List<Tree> members) {
       case ASTNode.ANNOTATION_TYPE_DECLARATION,
         ASTNode.ENUM_DECLARATION,
         ASTNode.RECORD_DECLARATION,
-        ASTNode.TYPE_DECLARATION:
+        ASTNode.TYPE_DECLARATION,
+        ASTNode.UNNAMED_CLASS:
         lastTokenIndex = processTypeDeclaration((AbstractTypeDeclaration) node, members);
         break;
       case ASTNode.ANNOTATION_TYPE_MEMBER_DECLARATION:
diff --git a/java-frontend/src/main/java/org/sonar/java/model/declaration/ClassTreeImpl.java b/java-frontend/src/main/java/org/sonar/java/model/declaration/ClassTreeImpl.java
@@ -43,8 +43,10 @@
 public class ClassTreeImpl extends JavaTree implements ClassTree {
 
   private final Kind kind;
+  @Nullable
   private final SyntaxToken openBraceToken;
   private final List<Tree> members;
+  @Nullable
   private final SyntaxToken closeBraceToken;
   private ModifiersTree modifiers;
   private SyntaxToken atToken;
@@ -69,7 +71,7 @@ public class ClassTreeImpl extends JavaTree implements ClassTree {
   @Nullable
   public ITypeBinding typeBinding;
 
-  public ClassTreeImpl(Kind kind, SyntaxToken openBraceToken, List<Tree> members, SyntaxToken closeBraceToken) {
+  public ClassTreeImpl(Kind kind, @Nullable SyntaxToken openBraceToken, List<Tree> members, @Nullable SyntaxToken closeBraceToken) {
     this.kind = kind;
     this.openBraceToken = openBraceToken;
     this.members = orderMembers(kind, members);
@@ -197,6 +199,7 @@ public ListTree<TypeTree> permittedTypes() {
     return permittedTypes;
   }
 
+  @Nullable
   @Override
   public SyntaxToken openBraceToken() {
     return openBraceToken;
@@ -207,6 +210,7 @@ public List<Tree> members() {
     return members;
   }
 
+  @Nullable
   @Override
   public SyntaxToken closeBraceToken() {
     return closeBraceToken;
@@ -262,9 +266,9 @@ public List<Tree> children() {
       addIfNotNull(implementsKeyword),
       Collections.singletonList(superInterfaces),
       Collections.singletonList(permittedTypes),
-      Collections.singletonList(openBraceToken),
+      addIfNotNull(openBraceToken),
       members,
-      Collections.singletonList(closeBraceToken)
+      addIfNotNull(closeBraceToken)
     );
   }
 
diff --git a/java-frontend/src/main/java/org/sonar/plugins/java/api/tree/Tree.java b/java-frontend/src/main/java/org/sonar/plugins/java/api/tree/Tree.java
@@ -78,6 +78,13 @@ enum Kind implements GrammarRuleKey {
      */
     RECORD(ClassTree.class),
 
+    /**
+     * {@link ClassTree}
+     *
+     * @since Java 25
+     */
+    IMPLICIT_CLASS(ClassTree.class),
+
     /**
      * {@link EnumConstantTree}
      *
diff --git a/java-frontend/src/test/files/metrics/CompactSource.java b/java-frontend/src/test/files/metrics/CompactSource.java
@@ -0,0 +1,10 @@
+void main() {
+  int a = 5;
+  int x = 10;
+  float b = 3.14f;
+  System.out.println(a);
+  System.out.println(x);
+  System.out.println(b);
+}
+
+int x = 20;
diff --git a/java-frontend/src/test/java/org/sonar/java/JavaFilesCacheTest.java b/java-frontend/src/test/java/org/sonar/java/JavaFilesCacheTest.java
@@ -44,4 +44,14 @@ void resource_file_mapping() {
         "org/sonar/java/JavaFilesCacheTestFile$A$3");
   }
 
+  @Test
+  void compact_source() {
+    JavaFilesCache javaFilesCache = new JavaFilesCache();
+    JavaAstScanner.scanSingleFileForTests(TestUtils.inputFile("src/test/resources/JavaFilesCacheTestFileCompact.java"), new VisitorsBridge(javaFilesCache));
+
+    Set<String> classNames = javaFilesCache.getClassNames();
+    assertThat(classNames)
+      .hasSize(4)
+      .contains("$1$1", "$1", "$1$C", "$1$C$D");
+  }
 }
diff --git a/java-frontend/src/test/java/org/sonar/java/MeasurerTest.java b/java-frontend/src/test/java/org/sonar/java/MeasurerTest.java
@@ -77,6 +77,11 @@ void verify_statements_metric() {
     checkMetric("Statements.java", "statements", 18);
   }
 
+  @Test
+  void verify_compact_source() {
+    checkMetric("CompactSource.java", "classes", 1);
+  }
+
   @Test
   void verify_ncloc_metric() {
     checkMetric("LinesOfCode.java", "ncloc", 2);
diff --git a/java-frontend/src/test/java/org/sonar/java/ast/visitors/PublicApiCheckerTest.java b/java-frontend/src/test/java/org/sonar/java/ast/visitors/PublicApiCheckerTest.java
@@ -49,15 +49,15 @@ void private_constructor() throws Exception {
   @Test
   void targeted_kinds() {
     assertThat(PublicApiChecker.classKinds())
-      .hasSize(5)
-      .containsExactlyInAnyOrder(Tree.Kind.ANNOTATION_TYPE, Tree.Kind.ENUM, Tree.Kind.CLASS, Tree.Kind.INTERFACE, Tree.Kind.RECORD);
+      .hasSize(6)
+      .containsExactlyInAnyOrder(Tree.Kind.ANNOTATION_TYPE, Tree.Kind.ENUM, Tree.Kind.CLASS, Tree.Kind.INTERFACE, Tree.Kind.RECORD, Tree.Kind.IMPLICIT_CLASS);
 
     assertThat(PublicApiChecker.methodKinds())
       .hasSize(2)
       .containsExactlyInAnyOrder(Tree.Kind.CONSTRUCTOR, Tree.Kind.METHOD);
 
     assertThat(PublicApiChecker.apiKinds())
-      .hasSize(8)
+      .hasSize(9)
       .contains(PublicApiChecker.classKinds())
       .contains(PublicApiChecker.methodKinds())
       .contains(Tree.Kind.VARIABLE);
diff --git a/java-frontend/src/test/java/org/sonar/java/model/JParserSemanticTest.java b/java-frontend/src/test/java/org/sonar/java/model/JParserSemanticTest.java
@@ -2102,4 +2102,43 @@ public class Source {
     JavaTree.ImportTreeImpl importConst = (JavaTree.ImportTreeImpl) cu.imports().get(1);
     assertThat(importConst.isModule()).isFalse();
   }
+
+  @Test
+  void compactSource_simple() {
+    String source = """
+      void main() {
+      }
+    """;
+    JavaTree.CompilationUnitTreeImpl cu = test(source);
+    assertThat(cu.types()).hasSize(1);
+    ClassTreeImpl clazz = (ClassTreeImpl) cu.types().get(0);
+    assertThat(clazz).isNotNull();
+    assertThat(clazz.kind()).isEqualTo(Tree.Kind.IMPLICIT_CLASS);
+    assertThat(clazz.simpleName()).isNull();
+    assertThat(clazz.openBraceToken()).isNull();
+    assertThat(clazz.closeBraceToken()).isNull();
+  }
+
+  @Test
+  void compactSource_complex() {
+    String source = """
+      void main() {
+        System.out.println("Hello, World!");
+      }
+      int i = 43;
+      class Helper {
+        void help() {
+          System.out.println("Helping...");
+        }
+      }
+    """;
+    JavaTree.CompilationUnitTreeImpl cu = test(source);
+    ClassTreeImpl clazz = (ClassTreeImpl) cu.types().get(0);
+    assertThat(clazz).isNotNull();
+    assertThat(clazz.kind()).isEqualTo(Tree.Kind.IMPLICIT_CLASS);
+    assertThat(clazz.members()).hasSize(3);
+    assertThat(clazz.members().get(0).kind()).isEqualTo(Tree.Kind.METHOD);
+    assertThat(clazz.members().get(1).kind()).isEqualTo(Tree.Kind.VARIABLE);
+    assertThat(clazz.members().get(2).kind()).isEqualTo(Tree.Kind.CLASS);
+  }
 }
diff --git a/java-frontend/src/test/java/org/sonar/plugins/java/api/tree/TreeTest.java b/java-frontend/src/test/java/org/sonar/plugins/java/api/tree/TreeTest.java
@@ -24,7 +24,7 @@ class TreeTest {
 
   @Test
   void test() {
-    assertThat(Tree.Kind.values()).hasSize(128);
+    assertThat(Tree.Kind.values()).hasSize(129);
   }
 
 }
diff --git a/java-frontend/src/test/resources/JavaFilesCacheTestFileCompact.java b/java-frontend/src/test/resources/JavaFilesCacheTestFileCompact.java

Original file line number	Diff line number	Diff line change
`@@ -40,4 +40,11 @@ void test_records() {`
`40`	`40`	`.verifyIssues();`
`41`	`41`	`}`
`42`	`42`
	`43`	`+ @Test`
	`44`	`+ void test_compact_source() {`
	`45`	`+ CheckVerifier.newVerifier()`
	`46`	`+ .onFile(mainCodeSourcesPath("checks/HiddenFieldCheckCompactSample.java"))`
	`47`	`+ .withCheck(new HiddenFieldCheck())`
	`48`	`+ .verifyIssues();`
	`49`	`+ }`
`43`	`50`	`}`
Original file line number	Diff line number	Diff line change
`@@ -57,4 +57,12 @@ void tolerates_line_breaking_control_characters() {`
`57`	`57`	`.withCheck(new IndentationCheck())`
`58`	`58`	`.verifyNoIssues();`
`59`	`59`	`}`
	`60`	`+`
	`61`	`+ @Test`
	`62`	`+ void compact_source_file() {`
	`63`	`+ CheckVerifier.newVerifier()`
	`64`	`+ .onFile(mainCodeSourcesPath("checks/IndentationCheck_compactSource.java"))`
	`65`	`+ .withCheck(new IndentationCheck())`
	`66`	`+ .verifyIssues();`
	`67`	`+ }`
`60`	`68`	`}`