SONARJAVA-4904 FP on S1301 when using switch statement with type/reco…

…rd/guarded patterns

java-checks/src/main/java/org/sonar/java/checks/SwitchAtLeastThreeCasesCheck.java

@@ -43,11 +43,22 @@ public void visitNode(Tree tree) {
     SwitchStatementTree switchStatementTree = (SwitchStatementTree) tree;
     int count = 0;
     for (CaseGroupTree caseGroup : switchStatementTree.cases()) {
+      // whenever there is a type, record or guarded pattern, it would decrease readability to replace the switch by if
+      // so we don't raise an issue
+      if (hasLabelWithAllowedPattern(caseGroup)) {
+        return;
+      }
       count += caseGroup.labels().size();
     }
     if (count < 3) {
       reportIssue(switchStatementTree.switchKeyword(), "Replace this \"switch\" statement by \"if\" statements to increase readability.");
     }
   }
 
+  private static boolean hasLabelWithAllowedPattern(CaseGroupTree caseGroupTree) {
+    return caseGroupTree.labels().stream()
+      .flatMap(label -> label.expressions().stream())
+      .anyMatch(expression -> expression.is(Tree.Kind.TYPE_PATTERN, Tree.Kind.RECORD_PATTERN, Tree.Kind.GUARDED_PATTERN));
+  }
+
 }

java-checks/src/test/files/checks/SwitchAtLeastThreeCasesCheck.java

@@ -1,4 +1,39 @@
 class A {
+
+  static void recordSwitch1(MyRecord object) {
+    switch (object) { // Compliant
+      case String x when x.length() > 42 -> { }
+      case Integer i -> { }
+    }
+  }
+
+  static void recordSwitch1(Object object) {
+    switch (object) { // Compliant
+      case MyRecord(int x, int y) -> { }
+      case String s -> { }
+    }
+  }
+
+  public interface SealedClass {
+    sealed interface Shape permits Box, Circle {}
+    record Box() implements Shape { }
+    record Circle() implements Shape {}
+
+    void foo(Shape shape) {
+      switch (shape) { // Compliant because of type pattern matching
+        case Box ignored -> { }
+        case Circle ignored -> System.out.println();
+      }
+    }
+
+    void goo(Shape shape) {
+      switch (shape) { // Compliant because of type pattern matching
+        default -> System.out.println();
+        case Box ignored -> { }
+      }
+    }
+  }
+
   public void f() {
     switch (variable) { // Noncompliant [[sc=5;ec=11]] {{Replace this "switch" statement by "if" statements to increase readability.}}
       case 0: