add unnamed class feature and check for usage

GitOrigin-RevId: 51ab72778378fdf84d19cb801b10ef9fb1eb2929

java/java-analysis-api/resources/messages/JavaAnalysisBundle.properties

@@ -136,6 +136,7 @@ feature.record.patterns.in.for.each=Record patterns in for-each loops
 feature.enum.qualified.name.in.switch=Qualified enum as a constant in switch
 feature.string.templates=String templates
 feature.unnamed.vars=Unnamed patterns and variables
+feature.unnamed.classes=Unnamed classes
 
 find.searching.for.references.to.class.progress=Searching for references to class {0}...
 find.usages.panel.title.derived.classes.cap=Derived classes

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightVisitorImpl.java

@@ -569,6 +569,7 @@ public class HighlightVisitorImpl extends JavaElementVisitor implements Highligh
   @Override
   public void visitClassInitializer(@NotNull PsiClassInitializer initializer) {
     super.visitClassInitializer(initializer);
+    if (!myHolder.hasErrorResults()) add(checkUnnamedClassMember(initializer));
     if (!myHolder.hasErrorResults()) add(HighlightClassUtil.checkIllegalInstanceMemberInRecord(initializer));
     if (!myHolder.hasErrorResults()) add(HighlightControlFlowUtil.checkInitializerCompleteNormally(initializer));
     if (!myHolder.hasErrorResults()) add(HighlightControlFlowUtil.checkUnreachableStatement(initializer.getBody()));
@@ -735,6 +736,7 @@ public class HighlightVisitorImpl extends JavaElementVisitor implements Highligh
   @Override
   public void visitField(@NotNull PsiField field) {
     super.visitField(field);
+    if (!myHolder.hasErrorResults()) add(checkUnnamedClassMember(field));
     if (!myHolder.hasErrorResults()) add(HighlightClassUtil.checkIllegalInstanceMemberInRecord(field));
     if (!myHolder.hasErrorResults()) add(HighlightControlFlowUtil.checkFinalFieldInitialized(field));
   }
@@ -993,6 +995,7 @@ public class HighlightVisitorImpl extends JavaElementVisitor implements Highligh
   @Override
   public void visitMethod(@NotNull PsiMethod method) {
     super.visitMethod(method);
+    if (!myHolder.hasErrorResults()) add(checkUnnamedClassMember(method));
     if (!myHolder.hasErrorResults()) add(HighlightControlFlowUtil.checkUnreachableStatement(method.getBody()));
     if (!myHolder.hasErrorResults()) add(HighlightMethodUtil.checkConstructorHandleSuperClassExceptions(method));
     if (!myHolder.hasErrorResults()) add(HighlightMethodUtil.checkRecursiveConstructorInvocation(method));
@@ -2201,10 +2204,11 @@ public class HighlightVisitorImpl extends JavaElementVisitor implements Highligh
     }
   }
 
-  @Override
-  public void visitUnnamedPattern(@NotNull PsiUnnamedPattern pattern) {
-    super.visitUnnamedPattern(pattern);
-    add(checkFeature(pattern, HighlightingFeature.UNNAMED_PATTERNS_AND_VARIABLES));
+  private HighlightInfo.Builder checkUnnamedClassMember(@NotNull PsiMember member) {
+    if (!(member.getContainingClass() instanceof PsiUnnamedClass)) {
+      return null;
+    }
+    return checkFeature(member, HighlightingFeature.UNNAMED_CLASSES);
   }
 
   private HighlightInfo.Builder checkFeature(@NotNull PsiElement element, @NotNull HighlightingFeature feature) {

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightingFeature.java

@@ -77,6 +77,7 @@ public enum HighlightingFeature {
       return until == useSiteLevel;
     }
 
+
     @Override
     boolean isLimited() {
       return true;
@@ -84,7 +85,7 @@ public enum HighlightingFeature {
   },
   ENUM_QUALIFIED_NAME_IN_SWITCH(LanguageLevel.JDK_21, "feature.enum.qualified.name.in.switch"),
   STRING_TEMPLATES(LanguageLevel.JDK_21_PREVIEW, "feature.string.templates"),
-  UNNAMED_PATTERNS_AND_VARIABLES(LanguageLevel.JDK_21_PREVIEW, "feature.unnamed.vars");
+  UNNAMED_CLASSES(LanguageLevel.JDK_21_PREVIEW, "feature.unnamed.classes");
 
   public static final @NonNls String JDK_INTERNAL_PREVIEW_FEATURE = "jdk.internal.PreviewFeature";
   public static final @NonNls String JDK_INTERNAL_JAVAC_PREVIEW_FEATURE = "jdk.internal.javac.PreviewFeature";

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/unnamedClass/HighlightInsufficientLevel.java

@@ -0,0 +1,13 @@
+<error descr="Unnamed classes are not supported at language level '20'">void foo() {
+
+}</error>
+
+<error descr="Unnamed classes are not supported at language level '20'">String s = "asd";</error>
+
+<error descr="Unnamed classes are not supported at language level '20'">static {
+
+}</error>
+
+class A {
+
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/UnnamedClassHighlightingTest.kt

@@ -0,0 +1,23 @@
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.java.codeInsight.daemon
+
+import com.intellij.JavaTestUtil
+import com.intellij.pom.java.LanguageLevel
+import com.intellij.testFramework.IdeaTestUtil
+import com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase
+
+class UnnamedClassHighlightingTest : LightJavaCodeInsightFixtureTestCase() {
+  override fun getProjectDescriptor() = JAVA_21
+  override fun getBasePath() = JavaTestUtil.getRelativeJavaTestDataPath() + "/codeInsight/daemonCodeAnalyzer/unnamedClass"
+
+  fun testHighlightInsufficientLevel() {
+    IdeaTestUtil.withLevel(module, LanguageLevel.JDK_20, Runnable {
+      doTest()
+    })
+  }
+
+  private fun doTest() {
+    myFixture.configureByFile(getTestName(false) + ".java")
+    myFixture.checkHighlighting()
+  }
+}