[java-completion] IDEA-324653 No completion for qualified Enum in switch

GitOrigin-RevId: 60392ce4c67348dfe05d558fc88f62884300f553

java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java

@@ -313,12 +313,17 @@ public final class JavaCompletionContributor extends CompletionContributor imple
       return new OrFilter(new ClassFilter(PsiClass.class), constantVariablesFilter);
     }
 
-    PsiClass typeClass = PsiUtil.resolveClassInType(selectorType);
-
     ClassFilter inheritorsFilter = new ClassFilter(PsiClass.class) {
       @Override
       public boolean isAcceptable(Object element, PsiElement context) {
-        return element instanceof PsiClass psiClass && InheritanceUtil.isInheritorOrSelf(psiClass, typeClass, true);
+        return element instanceof PsiClass psiClass && TypeConversionUtil.areTypesConvertible(TypeUtils.getType(psiClass), selectorType);
+      }
+    };
+
+    ClassFilter enumInheritorsFilter = new ClassFilter(PsiField.class) {
+      @Override
+      public boolean isAcceptable(Object element, PsiElement context) {
+        return element instanceof PsiEnumConstant enumConstant && TypeConversionUtil.areTypesConvertible(enumConstant.getType(), selectorType);
       }
     };
 
@@ -327,7 +332,7 @@ public final class JavaCompletionContributor extends CompletionContributor imple
     }
 
     return selectorType instanceof PsiClassType
-           ? inheritorsFilter
+           ? new OrFilter(inheritorsFilter, enumInheritorsFilter)
            : TrueFilter.INSTANCE;
   }
 

java/java-tests/testData/codeInsight/completion/normal/ClassPatternInSwitch1.java

@@ -0,0 +1,11 @@
+class Main {
+  sealed interface I{}
+  enum ENNNNN  implements I{AAA}
+  final class AAA implements I{}
+
+  public static void test3(I en) {
+    switch (en) {
+      case ENNN<caret>
+    }
+  }
+}

java/java-tests/testData/codeInsight/completion/normal/ClassPatternInSwitch1_after.java

@@ -0,0 +1,11 @@
+class Main {
+  sealed interface I{}
+  enum ENNNNN  implements I{AAA}
+  final class AAA implements I{}
+
+  public static void test3(I en) {
+    switch (en) {
+        case ENNNNN<caret>
+    }
+  }
+}

java/java-tests/testData/codeInsight/completion/normal/ClassPatternInSwitch2.java

@@ -0,0 +1,11 @@
+class Main {
+  interface I{}
+  enum ENNNNN  implements I{AAA}
+  final class AAAAAA implements I{}
+
+  public static void test3(I en) {
+    switch (en) {
+      case AAAA<caret>
+    }
+  }
+}

java/java-tests/testData/codeInsight/completion/normal/ClassPatternInSwitch2_after.java

@@ -0,0 +1,11 @@
+class Main {
+  interface I{}
+  enum ENNNNN  implements I{AAA}
+  final class AAAAAA implements I{}
+
+  public static void test3(I en) {
+    switch (en) {
+        case AAAAAA<caret>
+    }
+  }
+}

java/java-tests/testData/codeInsight/completion/normal/QualifierEnumConstantInSwitch1.java

@@ -0,0 +1,10 @@
+class Main {
+  sealed interface I{}
+  enum EN  implements I{AAA}
+
+  public static void test3(I en) {
+    switch (en) {
+      case EN.A<caret>
+    }
+  }
+}

java/java-tests/testData/codeInsight/completion/normal/QualifierEnumConstantInSwitch1_after.java

@@ -0,0 +1,10 @@
+class Main {
+  sealed interface I{}
+  enum EN  implements I{AAA}
+
+  public static void test3(I en) {
+    switch (en) {
+        case EN.AAA -> <caret>
+    }
+  }
+}

java/java-tests/testData/codeInsight/completion/normal/QualifierEnumConstantInSwitch2.java

@@ -0,0 +1,10 @@
+class Main {
+  sealed interface I{}
+  enum EN  implements I{AAA}
+
+  public static void test3(EN en) {
+    switch (en) {
+      case EN.A<caret>
+    }
+  }
+}

java/java-tests/testData/codeInsight/completion/normal/QualifierEnumConstantInSwitch2_after.java

@@ -0,0 +1,10 @@
+class Main {
+  sealed interface I{}
+  enum EN  implements I{AAA}
+
+  public static void test3(EN en) {
+    switch (en) {
+        case EN.AAA -> <caret>
+    }
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalSwitchCompletionTest.java

@@ -79,6 +79,10 @@ public class NormalSwitchCompletionTest extends NormalCompletionTestCase {
   public void testCompleteYieldInsideSwitch() { doTest(); }
   public void testWhenInSwitchRule() { doTest(); }
 
+  public void testQualifierEnumConstantInSwitch1() { doTest(); }
+  public void testQualifierEnumConstantInSwitch2() { doTest(); }
+  public void testClassPatternInSwitch1() { doTest(); }
+  public void testClassPatternInSwitch2() { doTest(); }
   private void doTestPostfixCompletion() {
     LiveTemplateCompletionContributor.setShowTemplatesInTests(true, myFixture.getTestRootDisposable());
     configure();