SONARJAVA-4908 Fix FP on S131 with type patterns in switch case claus…

…es (#4714)
SonarSource · Mar 15, 2024 · 30f96fa · 30f96fa
1 parent 23337de
commit 30f96fa
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Showing 2 changed files with 59 additions and 2 deletions.
diff --git a/java-checks-test-sources/default/src/main/java/checks/SwitchLastCaseIsDefaultCheck.java b/java-checks-test-sources/default/src/main/java/checks/SwitchLastCaseIsDefaultCheck.java
@@ -52,6 +52,58 @@ void foo(MyEnum myEnum, DayOfWeek dow) {
         break;
     }
   }
+
+  sealed interface Animal permits Cat, Dog, Phoenix {}
+  record Cat() implements Animal { }
+  record Dog() implements Animal { }
+  record Phoenix() implements Animal { }
+
+  static void sealedClass(Animal animal) {
+    switch (animal) { // Compliant
+      case Cat ignored -> { }
+      case Dog ignored -> { }
+      case Phoenix ignored -> { }
+    }
+  }
+
+  static void incompleteSealedClass(Animal animal) {
+    switch (animal) { // Compliant
+      case Cat ignored -> { }
+      default -> { }
+    }
+  }
+
+  static void typePattern(Object object) {
+    switch (object) { // Compliant
+      case String s -> { }
+      case Number n -> { }
+      case Object o -> { } // alternative to default
+    }
+  }
+
+  static void typePatternWithDefault(CharSequence cs) {
+    switch (cs) { // Compliant
+      case String s -> { }
+      case CharSequence c -> { } // type of the expression
+    }
+  }
+
+  static void typePatternWithDefault(Object object) {
+    switch (object) { // Compliant
+      case String s -> { }
+      case Number n -> { }
+      default -> { }
+    }
+  }
+
+  record MyRecord(int x, int y) { }
+
+  static void recordSwitch1(MyRecord object) {
+    switch (object) { // Compliant
+      case MyRecord(int x, int y) when x > 42 -> { }
+      case MyRecord(int x, int y) -> { }
+    }
+  }
 }
 
 enum MyEnum {

diff --git a/java-checks/src/main/java/org/sonar/java/checks/SwitchLastCaseIsDefaultCheck.java b/java-checks/src/main/java/org/sonar/java/checks/SwitchLastCaseIsDefaultCheck.java
@@ -46,7 +46,7 @@ public List<Tree.Kind> nodesToVisit() {
   @Override
   public void visitNode(Tree tree) {
     SwitchStatementTree switchStatementTree = (SwitchStatementTree) tree;
-    if (getDefaultLabel(switchStatementTree)) {
+    if (missesDefaultLabel(switchStatementTree) && !isSwitchOnTypePattern(switchStatementTree)) {
       if (!isSwitchOnEnum(switchStatementTree)) {
         reportIssue(switchStatementTree.switchKeyword(), "Add a default case to this switch.");
       } else if (missingCasesOfEnum(switchStatementTree)) {
@@ -55,7 +55,7 @@ public void visitNode(Tree tree) {
     }
   }
 
-  private static boolean getDefaultLabel(SwitchStatementTree switchStatementTree) {
+  private static boolean missesDefaultLabel(SwitchStatementTree switchStatementTree) {
     return allLabels(switchStatementTree).noneMatch(SwitchLastCaseIsDefaultCheck::isDefault);
   }
 
@@ -66,6 +66,11 @@ private static boolean isDefault(CaseLabelTree caseLabelTree) {
     return caseLabelTree.expressions().stream().anyMatch(expr -> expr.is(Tree.Kind.DEFAULT_PATTERN));
   }
 
+  private static boolean isSwitchOnTypePattern(SwitchStatementTree switchStatementTree) {
+    return allExpressions(switchStatementTree)
+      .anyMatch(expression -> expression.is(Tree.Kind.TYPE_PATTERN, Tree.Kind.RECORD_PATTERN, Tree.Kind.GUARDED_PATTERN));
+  }
+
   private static boolean equalsDefaultKeyword(String text) {
     return DEFAULT_LABEL_STRING.equals(text);
   }