Issue checkstyle#15107: Add input file for guarded pattern syntax in …

…MagicNumberCheck

src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/MagicNumberCheckTest.java

@@ -727,4 +727,21 @@ public void testMagicNumber3() throws Exception {
         verifyWithInlineConfigParser(
                 getPath("InputMagicNumberMagicNumber3.java"), expected);
     }
+
+    @Test
+    public void testMagicNumberInGuards() throws Exception {
+        final String[] expected = {
+            "21:63: " + getCheckMessage(MSG_KEY, "3"),
+            "21:72: " + getCheckMessage(MSG_KEY, "8"),
+            "27:58: " + getCheckMessage(MSG_KEY, "3"),
+            "27:68: " + getCheckMessage(MSG_KEY, "6"),
+            "31:50: " + getCheckMessage(MSG_KEY, "10.88"),
+            "33:46: " + getCheckMessage(MSG_KEY, "6"),
+            "39:59: " + getCheckMessage(MSG_KEY, "0.5"),
+            "39:67: " + getCheckMessage(MSG_KEY, "5"),
+            "44:23: " + getCheckMessage(MSG_KEY, "6"),
+        };
+        verifyWithInlineConfigParser(
+                getNonCompilablePath("InputMagicNumberMagicNumberInGuards.java"), expected);
+    }
 }

src/test/resources-noncompilable/com/puppycrawl/tools/checkstyle/checks/coding/magicnumber/InputMagicNumberMagicNumberInGuards.java

@@ -0,0 +1,51 @@
+/*
+MagicNumber
+ignoreNumbers = (default)-1, 0, 1, 2
+ignoreHashCodeMethod = (default)false
+ignoreAnnotation = (default)false
+ignoreFieldDeclaration = (default)false
+ignoreAnnotationElementDefaults = (default)true
+constantWaiverParentToken = (default)TYPECAST, METHOD_CALL, EXPR, ARRAY_INIT, UNARY_MINUS, \
+                            UNARY_PLUS, ELIST, STAR, ASSIGN, PLUS, MINUS, DIV, LITERAL_NEW
+tokens = (default)NUM_DOUBLE, NUM_FLOAT, NUM_INT, NUM_LONG
+
+
+*/
+
+//non-compiled with javac: Compilable with Java21
+package com.puppycrawl.tools.checkstyle.checks.coding.magicnumber;
+
+public class InputMagicNumberMagicNumberInGuards {
+
+    void m(Object o) {
+        if (o instanceof Point(int x, int y, double z) && x < 3 && y > 8) {}
+        // 2 violations above:
+        //                  ''3' is a magic number'
+       //                   ''8' is a magic number'
+
+        switch (o) {
+            case Point(int x, int y, double z) when (x < 3 && y != 6) -> {}
+             // 2 violations above:
+            //                  ''3' is a magic number.'
+            //                   ''6' is a magic number.'
+            case Point(_, _, double z) when z > (10.88) -> {}
+            // violation above, ''10.88' is a magic number'
+            case String s when s.length() != 6 -> {}
+            // violation above, ''6' is a magic number'
+            default -> {}
+        }
+
+        int w = switch (o) {
+            case Point(int x, int y, double z) when (z == 0.5) -> 5;
+             // 2 violations above:
+            //                  ''0.5' is a magic number.'
+           //                   ''5' is a magic number.'
+            case String s -> {
+                yield 6; // violation, ''6' is a magic number'
+            }
+            default -> 0;
+        };
+    }
+
+    record Point(int x, int y, double z) { }
+}