From 5e839de419955ca76e7cf53a4f540f3b1003bea2 Mon Sep 17 00:00:00 2001
From: Andrey Cherkasov <andrey.cherkasov@jetbrains.com>
Date: Thu, 23 Feb 2023 14:15:12 +0100
Subject: [PATCH] [java-highlighting] IDEA-313993 unreachable statement: false
 negative

GitOrigin-RevId: 396da7635b4bee1c921444c2b23f89f8c67e5895
---
 .../intellij/psi/controlFlow/ControlFlowAnalyzer.java  |  2 +-
 .../switchExpressions/EnhancedSwitchUnreachable.java   | 10 +++++++++-
 .../daemon/JavaSwitchExpressionsHighlightingTest.kt    |  4 +++-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowAnalyzer.java b/java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowAnalyzer.java
index 8c6e448ebaa2..5dc2cb59cf6c 100644
--- a/java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowAnalyzer.java
+++ b/java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowAnalyzer.java
@@ -979,7 +979,7 @@ final class ControlFlowAnalyzer extends JavaElementVisitor {
         if (labelElementList != null) {
           for (PsiCaseLabelElement element : labelElementList.getElements()) {
             if (element instanceof PsiDefaultCaseLabelElement ||
-                element instanceof PsiPattern && exprType != null && JavaPsiPatternUtil.isUnconditionalForType(element, exprType)) {
+                exprType != null && JavaPsiPatternUtil.isUnconditionalForType(element, exprType)) {
               needToCreateDefault = true;
               break;
             }
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/switchExpressions/EnhancedSwitchUnreachable.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/switchExpressions/EnhancedSwitchUnreachable.java
index 1273d940ead8..43d0fbd11ab8 100644
--- a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/switchExpressions/EnhancedSwitchUnreachable.java
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/switchExpressions/EnhancedSwitchUnreachable.java
@@ -1,5 +1,5 @@
 class C {
-  void alwaysThrow(String s) {
+  void alwaysThrow1(String s) {
     switch (s) {
       case "a" -> throw new IllegalArgumentException();
       default -> throw new IllegalStateException();
@@ -7,6 +7,14 @@ class C {
     <error descr="Unreachable statement">System.out.println();</error>
   }
 
+  void alwaysThrow2(Integer i) {
+    switch (i) {
+      case Integer integer when true:
+        throw new IllegalArgumentException();
+    }
+    <error descr="Unreachable statement">System.out.println(42);</error>
+  }
+
   void breakFromEndlessLoop() {
     EndlessLoop:
     for (;;) {
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/JavaSwitchExpressionsHighlightingTest.kt b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/JavaSwitchExpressionsHighlightingTest.kt
index 2c0066cf82a2..4923ff2a8ac0 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/JavaSwitchExpressionsHighlightingTest.kt
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/JavaSwitchExpressionsHighlightingTest.kt
@@ -3,6 +3,8 @@ package com.intellij.java.codeInsight.daemon
 
 import com.intellij.JavaTestUtil
 import com.intellij.codeInspection.redundantCast.RedundantCastInspection
+import com.intellij.pom.java.LanguageLevel
+import com.intellij.testFramework.IdeaTestUtil
 import com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase
 
 class JavaSwitchExpressionsHighlightingTest : LightJavaCodeInsightFixtureTestCase() {
@@ -16,7 +18,7 @@ class JavaSwitchExpressionsHighlightingTest : LightJavaCodeInsightFixtureTestCas
   fun testSwitchNumericPromotion() = doTest()
   fun testSimpleInferenceCases() = doTest()
   fun testEnhancedSwitchDefinitelyAssigned() = doTest()
-  fun testEnhancedSwitchUnreachable() = doTest()
+  fun testEnhancedSwitchUnreachable() = IdeaTestUtil.withLevel(module, LanguageLevel.JDK_20_PREVIEW) { doTest() }
   fun testSwitchExpressionHasResult() = doTest()
   fun testYieldStatements() = doTest()
   fun testAssignToFinalInSwitchExpression() = doTest()