Issue #12282: Resolve Pitest suppression for ParenPad

.ci/pitest-suppressions/pitest-whitespace-suppressions.xml

@@ -81,15 +81,6 @@
     <lineContent>processLeft(ast.findFirstToken(TokenTypes.LPAREN));</lineContent>
   </mutation>
 
-  <mutation unstable="false">
-    <sourceFile>ParenPadCheck.java</sourceFile>
-    <mutatedClass>com.puppycrawl.tools.checkstyle.checks.whitespace.ParenPadCheck</mutatedClass>
-    <mutatedMethod>visitToken</mutatedMethod>
-    <mutator>org.pitest.mutationtest.engine.gregor.mutators.experimental.RemoveSwitchMutator_3</mutator>
-    <description>RemoveSwitch 3 mutation</description>
-    <lineContent>switch (ast.getType()) {</lineContent>
-  </mutation>
-
   <mutation unstable="false">
     <sourceFile>ParenPadCheck.java</sourceFile>
     <mutatedClass>com.puppycrawl.tools.checkstyle.checks.whitespace.ParenPadCheck</mutatedClass>

src/main/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheck.java

@@ -263,13 +263,13 @@ public void visitToken(DetailAST ast) {
             case TokenTypes.ANNOTATION:
             case TokenTypes.ENUM_CONSTANT_DEF:
             case TokenTypes.LITERAL_NEW:
-            case TokenTypes.LITERAL_SYNCHRONIZED:
             case TokenTypes.LAMBDA:
                 visitTokenWithOptionalParentheses(ast);
                 break;
             case TokenTypes.RESOURCE_SPECIFICATION:
                 visitResourceSpecification(ast);
                 break;
+            case TokenTypes.LITERAL_SYNCHRONIZED:
             default:
                 processLeft(ast.findFirstToken(TokenTypes.LPAREN));
                 processRight(ast.findFirstToken(TokenTypes.RPAREN));

src/test/java/com/puppycrawl/tools/checkstyle/checks/whitespace/ParenPadCheckTest.java

@@ -25,6 +25,8 @@
 import static com.puppycrawl.tools.checkstyle.checks.whitespace.AbstractParenPadCheck.MSG_WS_NOT_PRECEDED;
 import static com.puppycrawl.tools.checkstyle.checks.whitespace.AbstractParenPadCheck.MSG_WS_PRECEDED;
 
+import com.puppycrawl.tools.checkstyle.api.Configuration;
+import com.puppycrawl.tools.checkstyle.checks.modifier.ModifierOrderCheck;
 import org.junit.jupiter.api.Test;
 
 import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
@@ -513,6 +515,13 @@ public void testParenPadCheckEmoji() throws Exception {
                 getPath("InputParenPadCheckEmoji.java"), expected);
     }
 
+    @Test
+    public void InputParenPadForSynchronized() throws Exception {
+        final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
+        verifyWithInlineConfigParser(
+                getPath("InputParenPadForSynchronized.java"), expected);
+    }
+
     /**
      * Pitest requires us to specify more concrete lower bound for condition for
      * ParenPadCheck#isAcceptableToken as nodes of first several types like CTOR_DEF,

src/test/resources/com/puppycrawl/tools/checkstyle/checks/whitespace/parenpad/InputParenPadForSynchronized.java

@@ -0,0 +1,34 @@
+/*
+ParenPad
+option = (default)nospace
+tokens = LITERAL_SYNCHRONIZED, CTOR_DEF, CTOR_CALL, LITERAL_IF
+
+
+*/
+
+package com.puppycrawl.tools.checkstyle.checks.whitespace.parenpad;
+
+/**
+ *
+ * Thread-safe Singleton class.
+ * The instance is lazily initialized and thus needs synchronization
+ * mechanism.
+ *
+ */
+class InputParenPadForSynchronized {
+
+    private static InputParenPadForSynchronized instance = null;
+    private InputParenPadForSynchronized() {
+    }
+
+    public synchronized static InputParenPadForSynchronized getInstance() {
+        /*
+         * The instance gets created only when it is called for first time.
+         * Lazy -loading
+         */
+        if(instance == null) {
+            instance = new InputParenPadForSynchronized();
+        }
+        return instance;
+    }
+}