SONARJAVA-5083 Add unit test samples for Java 22 unnamed variables and patterns (#4907)

Author: alban-auzeill

java-checks-test-sources/default/src/main/java/checks/unused/UnusedLocalVariableCheck.java

@@ -315,18 +315,25 @@ record ColoredPoint(Point p, String color) { }
 
   void unnamedVariablesUseCases(Queue<Ball> queue, BallHolder<? extends Ball> ballHolder, ColoredPoint coloredPoint) {
     int total = 0;
+    int _ = 1 + 1;
+    java.util.function.IntUnaryOperator _ = (int _) -> 0;
+    java.util.function.IntUnaryOperator _ = _ -> 0;
+    java.util.function.IntBinaryOperator _ = (_,_) -> 0;
+    java.util.function.IntBinaryOperator _ = (int _, int _) -> 0;
     for(Object _ : queue) { // Compliant
       total++;
     }
     System.out.println(total);
-
+    for (int i = 0, _ = 1 + 1; i < 2; i++) {
+      System.out.println(i);
+    }
     while(queue.size() > 2) {
       var a = queue.remove();
       var _ = queue.remove(); // Compliant
       System.out.println(a);
     }
 
-    try {
+    try (var _ = new java.io.FileInputStream("foo.txt")) {
       queue.remove();
     } catch (Exception _) { // Compliant
       System.out.println("Exception");

java-checks/src/main/java/org/sonar/java/checks/naming/BadLocalVariableNameCheck.java

@@ -29,6 +29,7 @@
 import org.sonar.plugins.java.api.tree.ClassTree;
 import org.sonar.plugins.java.api.tree.ForEachStatement;
 import org.sonar.plugins.java.api.tree.ForStatementTree;
+import org.sonar.plugins.java.api.tree.IdentifierTree;
 import org.sonar.plugins.java.api.tree.Tree;
 import org.sonar.plugins.java.api.tree.VariableTree;
 
@@ -92,8 +93,9 @@ public void visitCatch(CatchTree tree) {
 
   @Override
   public void visitVariable(VariableTree tree) {
-    if (!pattern.matcher(tree.simpleName().name()).matches() && !isLocalConstant(tree)) {
-      context.reportIssue(this, tree.simpleName(), "Rename this local variable to match the regular expression '" + format + "'.");
+    IdentifierTree simpleName = tree.simpleName();
+    if (!simpleName.isUnnamedVariable() && !pattern.matcher(simpleName.name()).matches() && !isLocalConstant(tree)) {
+      context.reportIssue(this, simpleName, "Rename this local variable to match the regular expression '" + format + "'.");
     }
     super.visitVariable(tree);
   }

java-checks/src/main/java/org/sonar/java/checks/unused/UnusedLocalVariableCheck.java

@@ -72,15 +72,17 @@ public void visitNode(Tree tree) {
   public void leaveNode(Tree tree) {
     if (tree.is(Tree.Kind.VARIABLE)) {
       VariableTree variable = (VariableTree) tree;
-      String name = variable.simpleName().name();
-      boolean unresolved = UNRESOLVED_IDENTIFIERS_AND_SWITCH_CASE_VISITOR.isUnresolved(name);
-      if (!unresolved && isProperLocalVariable(variable) && isUnused(variable.symbol())) {
-        QuickFixHelper.newIssue(context)
-          .forRule(this)
-          .onTree(variable.simpleName())
-          .withMessage(String.format(MESSAGE, name))
-          .withQuickFixes(() -> computeQuickFix(variable))
-          .report();
+      IdentifierTree simpleName = variable.simpleName();
+      if (!simpleName.isUnnamedVariable()) {
+        boolean unresolved = UNRESOLVED_IDENTIFIERS_AND_SWITCH_CASE_VISITOR.isUnresolved(simpleName.name());
+        if (!unresolved && isProperLocalVariable(variable) && isUnused(variable.symbol())) {
+          QuickFixHelper.newIssue(context)
+            .forRule(this)
+            .onTree(simpleName)
+            .withMessage(String.format(MESSAGE, simpleName.name()))
+            .withQuickFixes(() -> computeQuickFix(variable))
+            .report();
+        }
       }
     }
 

java-checks/src/test/files/checks/naming/BadLocalVariableNameNoncompliant.java

@@ -1,3 +1,5 @@
+import java.util.function.IntUnaryOperator;
+
 class BadLocalVariableName {
   void method(
     int BAD_FORMAL_PARAMETER // Noncompliant {{Rename this local variable to match the regular expression '^[a-z][a-zA-Z0-9]*$'.}}
@@ -36,4 +38,8 @@ void forEachMethod() {
     }
   }
 
+  void foo() {
+    IntUnaryOperator f1 = (int _) -> 0; // Compliant, unnamed variable
+    IntUnaryOperator f2 = _ -> 0; // Compliant, unnamed variable
+  }
 }