Issue checkstyle#14825: fix false positive for WhitespaceAroundCheck

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

@@ -497,22 +497,37 @@ public void visitToken(DetailAST ast) {
      */
     private boolean isNotRelevantSituation(DetailAST ast, int currentType) {
         final int parentType = ast.getParent().getType();
-        final boolean starImport = currentType == TokenTypes.STAR
-                && parentType == TokenTypes.DOT;
-        final boolean insideCaseGroup = parentType == TokenTypes.CASE_GROUP;
-
-        final boolean starImportOrSlistInsideCaseGroup = starImport || insideCaseGroup;
-        final boolean colonOfCaseOrDefaultOrForEach =
-                isColonOfCaseOrDefault(parentType)
-                        || isColonOfForEach(parentType);
-        final boolean emptyBlockOrType =
-                isEmptyBlock(ast, parentType)
+        final boolean result;
+        switch (parentType) {
+            case TokenTypes.DOT: {
+                result = currentType == TokenTypes.STAR;
+                break;
+            }
+            case TokenTypes.LITERAL_DEFAULT:
+            case TokenTypes.LITERAL_CASE:
+            case TokenTypes.CASE_GROUP: {
+                result = true;
+                break;
+            }
+            case TokenTypes.FOR_EACH_CLAUSE: {
+                result = ignoreEnhancedForColon;
+                break;
+            }
+            case TokenTypes.EXPR: {
+                result = currentType == TokenTypes.LITERAL_SWITCH;
+                break;
+            }
+            case TokenTypes.ARRAY_INIT:
+            case TokenTypes.ANNOTATION_ARRAY_INIT: {
+                result = currentType == TokenTypes.RCURLY;
+                break;
+            }
+            default: {
+                result = isEmptyBlock(ast, parentType)
                     || allowEmptyTypes && isEmptyType(ast);
-
-        return starImportOrSlistInsideCaseGroup
-                || colonOfCaseOrDefaultOrForEach
-                || emptyBlockOrType
-                || isArrayInitialization(currentType, parentType);
+            }
+        }
+        return result;
     }
 
     /**
@@ -615,41 +630,6 @@ private static boolean isEmptyBlock(DetailAST ast, int parentType, int match) {
         return result;
     }
 
-    /**
-     * Whether colon belongs to cases or defaults.
-     *
-     * @param parentType parent
-     * @return true if current token in colon of case or default tokens
-     */
-    private static boolean isColonOfCaseOrDefault(int parentType) {
-        return parentType == TokenTypes.LITERAL_DEFAULT
-                    || parentType == TokenTypes.LITERAL_CASE;
-    }
-
-    /**
-     * Whether colon belongs to for-each.
-     *
-     * @param parentType parent
-     * @return true if current token in colon of for-each token
-     */
-    private boolean isColonOfForEach(int parentType) {
-        return parentType == TokenTypes.FOR_EACH_CLAUSE
-                && ignoreEnhancedForColon;
-    }
-
-    /**
-     * Is array initialization.
-     *
-     * @param currentType current token
-     * @param parentType parent token
-     * @return true is current token inside array initialization
-     */
-    private static boolean isArrayInitialization(int currentType, int parentType) {
-        return currentType == TokenTypes.RCURLY
-                && (parentType == TokenTypes.ARRAY_INIT
-                        || parentType == TokenTypes.ANNOTATION_ARRAY_INIT);
-    }
-
     /**
      * Test if the given {@code DetailAST} is part of an allowed empty
      * method block.

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

@@ -260,6 +260,13 @@ public void testSwitchWhitespaceAround() throws Exception {
                 getPath("InputWhitespaceAroundSwitch.java"), expected);
     }
 
+    @Test
+    public void testSwitchExpressionWhitespaceAround() throws Exception {
+        final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
+        verifyWithInlineConfigParser(
+                getNonCompilablePath("InputWhitespaceAroundSwitchExpressions.java"), expected);
+    }
+
     @Test
     public void testDoWhileWhitespaceAround() throws Exception {
         final String[] expected = {

src/test/resources-noncompilable/com/puppycrawl/tools/checkstyle/checks/whitespace/whitespacearound/InputWhitespaceAroundSwitchExpressions.java

@@ -0,0 +1,38 @@
+/*
+WhitespaceAround
+allowEmptyConstructors = (default)false
+allowEmptyMethods = (default)false
+allowEmptyTypes = (default)false
+allowEmptyLoops = (default)false
+allowEmptyLambdas = (default)false
+allowEmptyCatches = (default)false
+ignoreEnhancedForColon = (default)true
+tokens = (default)ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, \
+         BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND, \
+         LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, \
+         LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED, \
+         LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN, \
+         NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR, \
+         SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND
+
+
+*/
+
+package com.puppycrawl.tools.checkstyle.checks.whitespace.whitespacearound;
+
+import java.util.Optional;
+
+public class InputWhitespaceAroundSwitchExpressions {
+
+    Optional<String> someMethod(int arg) {
+        return Optional.ofNullable(switch (arg) { // ok - switch expression
+            default -> null;
+        });
+    }
+
+    Optional<String> someMethod2(int arg) {
+        return Optional.ofNullable(((switch (arg) { // ok - switch expression
+            default -> null;
+        })));
+    }
+}