From eb237655386cbcfe65f3c0cff73cb2e6e8c582ca Mon Sep 17 00:00:00 2001
From: Alexandr Suhinin <alexandr.suhinin@jetbrains.com>
Date: Fri, 28 Oct 2022 14:13:16 +0300
Subject: [PATCH] IDEA-302550 [java highlighting] switch exhaustiveness:
 consider permitted classes inside pattern check

GitOrigin-RevId: 14c74921fb72a7915ad0c017cc1cafbab1ee5534
---
 .../SwitchBlockHighlightingModel.java         | 17 ++++++++++++++++
 ...hExhaustivenessWithSealedIntersection.java | 20 +++++++++++++++++++
 ...ightPatternsForSwitchHighlightingTest.java |  4 ++++
 3 files changed, 41 insertions(+)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/SwitchExhaustivenessWithSealedIntersection.java

diff --git a/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/SwitchBlockHighlightingModel.java b/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/SwitchBlockHighlightingModel.java
index e9e4e18a4aa7..5142010f45eb 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/SwitchBlockHighlightingModel.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/SwitchBlockHighlightingModel.java
@@ -31,6 +31,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
+import java.util.function.Consumer;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -391,11 +392,27 @@ public class SwitchBlockHighlightingModel {
       PsiClass patternClass = PsiUtil.resolveClassInClassTypeOnly(JavaPsiPatternUtil.getPatternType(element));
       if (patternClass != null) {
         patternClasses.put(patternClass, patternLabelElement);
+        visitAllPermittedClasses(patternClass, permittedClass -> patternClasses.put(permittedClass, patternLabelElement));
       }
     }
     return patternClasses;
   }
 
+  private static void visitAllPermittedClasses(@NotNull PsiClass psiClass, Consumer<PsiClass> consumer){
+    Set<PsiClass> visitedClasses = new HashSet<>();
+    Queue<PsiClass> notVisitedClasses = new LinkedList<>();
+    notVisitedClasses.add(psiClass);
+    while (!notVisitedClasses.isEmpty()) {
+      PsiClass notVisitedClass = notVisitedClasses.poll();
+      if (!notVisitedClass.hasModifierProperty(SEALED) || visitedClasses.contains(notVisitedClass)) continue;
+      visitedClasses.add(notVisitedClass);
+      for (PsiClass permittedClass : PatternsInSwitchBlockHighlightingModel.getPermittedClasses(psiClass)) {
+        consumer.accept(permittedClass);
+        notVisitedClasses.add(permittedClass);
+      }
+    }
+  }
+
   private static @NotNull Set<PsiClass> findMissedClasses(@NotNull PsiType selectorType, Map<PsiClass, PsiPattern> patternClasses) {
     PsiClass selectorClass = PsiUtil.resolveClassInClassTypeOnly(selectorType);
     if (selectorClass instanceof PsiTypeParameter) {
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/SwitchExhaustivenessWithSealedIntersection.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/SwitchExhaustivenessWithSealedIntersection.java
new file mode 100644
index 000000000000..efca50168612
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatternsInSwitch/SwitchExhaustivenessWithSealedIntersection.java
@@ -0,0 +1,20 @@
+sealed interface First {}
+sealed interface Second {}
+sealed interface Third extends First {}
+
+final class F1 implements First {}
+final class F2 implements First, Second {}
+final class F3 implements Second {}
+final class F4 implements Third, Second {} //implicit First
+
+class Test {
+  void test(First o) {
+    switch (o) {
+      case F1 x -> System.out.println();
+      case Second x -> System.out.println();
+    }
+    switch (<error descr="'switch' statement does not cover all possible input values">o</error>) {
+      case Second x -> System.out.println();
+    }
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsForSwitchHighlightingTest.java b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsForSwitchHighlightingTest.java
index c97d0d5eb51b..591344c2bf6c 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsForSwitchHighlightingTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsForSwitchHighlightingTest.java
@@ -53,6 +53,10 @@ public class LightPatternsForSwitchHighlightingTest extends LightJavaCodeInsight
     IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_19_PREVIEW, this::doTest);
   }
 
+  public void testSwitchExhaustivenessWithSealedIntersection(){
+    IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_19_PREVIEW, this::doTest);
+  }
+
   public void testSwitchExhaustivenessWithGenericsIn19Java() {
     IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_19_PREVIEW, this::doTest);
   }