[java-highlighting] IDEA-340211 Unnamed variables, turn on for java 22 (JEP 456)

- turn on for java 22
- add more tests for java 22

GitOrigin-RevId: 62b25e768ef827da94acffc8a9054c6b5775254e

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

@@ -89,7 +89,12 @@ 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_PATTERNS_AND_VARIABLES(LanguageLevel.JDK_22, "feature.unnamed.vars") {
+    @Override
+    boolean isSufficient(@NotNull LanguageLevel useSiteLevel) {
+      return super.isSufficient(useSiteLevel) || LanguageLevel.JDK_21_PREVIEW == useSiteLevel;
+    }
+  },
   UNNAMED_CLASSES(LanguageLevel.JDK_21_PREVIEW, "feature.unnamed.classes");
 
   public static final @NonNls String JDK_INTERNAL_PREVIEW_FEATURE = "jdk.internal.PreviewFeature";

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingPatterns/UnnamedPatternsJava22.java

@@ -0,0 +1,47 @@
+public class UnnamedPatterns {
+  record R(int a, int b) {}
+  
+  void test(Object obj) {
+    if (obj instanceof <error descr="Using '_' as a reference is not allowed">_</error>) {}
+    
+    if (obj instanceof R(_, _)) {}
+    if (obj instanceof R(int a, _)) {
+      System.out.println(a);
+    }
+    if (obj instanceof R(_, int b)) {
+      System.out.println(b);
+    }
+    if (obj instanceof R(_, _, <error descr="Incorrect number of nested patterns: expected 2 but found 3">_)</error>) {
+    }
+  }
+
+  void testSwitch(Object obj) {
+    switch (obj) {
+      case R(_, var b) -> {
+      }
+      case <error descr="Label is dominated by a preceding case label 'R(_, var b)'">R(var c, var b)</error> -> {
+      }
+      case <error descr="Label is dominated by a preceding case label 'R(_, var b)'">R(int a, _)</error> -> {
+      }
+      default -> {
+      }
+    }
+  }
+
+  void testExhaustiveness(I a) {
+    boolean r3 = switch (a) {
+      case R1(_) -> true;
+      case R2(_) -> false;
+    };
+  }
+
+  void testNonExhaustiveness(I a) {
+    boolean r3 = switch (<error descr="'switch' expression does not cover all possible input values">a</error>) {
+      case R1(_) -> true;
+    };
+  }
+
+  sealed interface I {};
+  record R1(int n1) implements I {};
+  record R2(int n1) implements I {};
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingUnnamed/UnnamedVariablesJava22.java

@@ -0,0 +1,57 @@
+import java.util.function.*;
+
+public class UnnamedVariables {
+  void testParameter(<error descr="Unnamed method parameter is not allowed">int _</error>, <error descr="Unnamed method parameter is not allowed">String _</error>) {
+    System.out.println(<error descr="Using '_' as a reference is not allowed">_</error>);
+  }
+  
+  <error descr="Unnamed field is not allowed">int _</error> = 123;
+  String s = <error descr="Using '_' as a reference is not allowed">_</error>;
+  
+  void testLambda() {
+    Consumer<String> consumer = _ -> System.out.println("Hello");
+    Consumer<String> consumer2 = _ -> System.out.println(<error descr="Using '_' as a reference is not allowed">_</error>);
+    Consumer<String> consumer3 = _ -> System.out.println(<error descr="Using '_' as a reference is not allowed">_</error>.trim());
+    Consumer<String> consumer4 = _ -> {
+      var v = <error descr="Using '_' as a reference is not allowed">_</error>;
+      System.out.println(v.<error descr="Cannot resolve method 'trim()'" textAttributesKey="WRONG_REFERENCES_ATTRIBUTES">trim</error>());
+    };
+    BiConsumer<String, String> consumer5 = (_,_) -> {};
+  }
+  
+  void testWhen(Object obj) {
+    switch (obj) {
+      case String _ when <error descr="Using '_' as a reference is not allowed">_</error>.isEmpty() -> {}
+    }
+  }
+  
+  void testLocal() {
+    int _ = 10;
+    int _ = 20;
+    int _<error descr="Brackets are not allowed after unnamed variable declaration ">[]</error> = {30};
+    int[] _ = {40};
+    var _ = "string";
+    for (int _ = 1;;) {}
+  }
+  
+  void testNoInitializer() {
+    <error descr="Unnamed variable declaration must have an initializer">int _</error>;
+    
+    for(<error descr="Unnamed variable declaration must have an initializer">int _</error>;;) {}
+  }
+  
+  void testCatch() {
+    try {
+      System.out.println();
+    }
+    catch (Exception _) {
+      System.out.println("ignore");
+    }
+    catch (Error _) {
+      int _ = 1;
+      for(int _:new int[10]) {
+        System.out.println("oops");
+      }
+    }
+  }
+}

java/java-tests/testData/inspection/dataFlow/fixture/UnnamedPatternsJava22.java

@@ -0,0 +1,25 @@
+class Test {
+  public static String testReach(Object o1, Object o2) {
+    return switch (o1) {
+      case String _ when o2 instanceof String s: yield s;
+      case Object _: yield "strange";
+    };
+  }
+
+  record R(int x, int y) {}
+  void test(Object obj) {
+    if (obj instanceof R(_, var b)) {
+      return;
+    }
+    if (<warning descr="Condition 'obj instanceof R(var a, var b)' is always 'false'">obj instanceof R(var a, var b)</warning>) {
+      return;
+    }
+    if (<warning descr="Condition 'obj instanceof R(int a, _)' is always 'false'">obj instanceof R(int a, _)</warning>) {
+      return;
+    }
+  }
+
+  public static void main(String[] args) {
+    System.out.println(testReach("1", "2"));
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/impl/quickfix/ChangeToUnnamedPatternTest.java

@@ -6,7 +6,7 @@ import com.intellij.codeInspection.deadCode.UnusedDeclarationInspectionBase;
 import com.intellij.testFramework.LightProjectDescriptor;
 import org.jetbrains.annotations.NotNull;
 
-import static com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase.JAVA_21;
+import static com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase.JAVA_22;
 
 public class ChangeToUnnamedPatternTest extends LightIntentionActionTestCase {
   @Override
@@ -18,7 +18,7 @@ public class ChangeToUnnamedPatternTest extends LightIntentionActionTestCase {
   @NotNull
   @Override
   protected LightProjectDescriptor getProjectDescriptor() {
-    return JAVA_21;
+    return JAVA_22;
   }
 
   @Override

java/java-tests/testSrc/com/intellij/codeInsight/daemon/impl/quickfix/RenameToUnnamedVariableTest.java

@@ -3,11 +3,10 @@ package com.intellij.codeInsight.daemon.impl.quickfix;
 
 import com.intellij.codeInsight.daemon.LightIntentionActionTestCase;
 import com.intellij.codeInspection.deadCode.UnusedDeclarationInspection;
-import com.intellij.codeInspection.deadCode.UnusedDeclarationInspectionBase;
 import com.intellij.testFramework.LightProjectDescriptor;
 import org.jetbrains.annotations.NotNull;
 
-import static com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase.JAVA_21;
+import static com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase.JAVA_22;
 
 public class RenameToUnnamedVariableTest extends LightIntentionActionTestCase {
   @Override
@@ -19,7 +18,7 @@ public class RenameToUnnamedVariableTest extends LightIntentionActionTestCase {
   @NotNull
   @Override
   protected LightProjectDescriptor getProjectDescriptor() {
-    return JAVA_21;
+    return JAVA_22;
   }
 
   @Override

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightPatternsHighlightingTest.java

@@ -98,9 +98,13 @@ public class LightPatternsHighlightingTest extends LightJavaCodeInsightFixtureTe
   }
   
   public void testUnnamedPatterns() {
-    doTest();
-  } 
-  
+    IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_21_PREVIEW, this::doTest);
+  }
+
+  public void testUnnamedPatternsJava22() {
+    IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_22, this::doTest);
+  }
+
   public void testUnnamedPatternsUnavailable() {
     IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_20, this::doTest);
   } 

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightUnnamedVariablesHighlightingTest.java

@@ -16,13 +16,17 @@ public class LightUnnamedVariablesHighlightingTest extends LightJavaCodeInsightF
 
   @Override
   protected @NotNull LightProjectDescriptor getProjectDescriptor() {
-    return JAVA_21;
+    return JAVA_22;
   }
 
   public void testUnnamedVariables() {
+    IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_21_PREVIEW, () -> doTest());
+  }
+
+  public void testUnnamedVariablesJava22() {
     doTest();
-  } 
-  
+  }
+
   public void testUnnamedVariablesInGuard() {
     doTest();
   } 

java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java

@@ -2,6 +2,8 @@
 package com.intellij.java.codeInspection;
 
 import com.intellij.JavaTestUtil;
+import com.intellij.pom.java.LanguageLevel;
+import com.intellij.testFramework.IdeaTestUtil;
 import com.intellij.testFramework.LightProjectDescriptor;
 import org.jetbrains.annotations.NotNull;
 
@@ -55,7 +57,11 @@ public class DataFlowInspection21Test extends DataFlowInspectionTestCase {
   public void testUnnamedPatterns() {
     doTest();
   }
-  
+
+  public void testUnnamedPatternsJava22() {
+    IdeaTestUtil.withLevel(getModule(), LanguageLevel.JDK_22, this::doTest);
+  }
+
   public void testPatternInStreamNotComplex() {
     doTest();
   }

java/testFramework/src/com/intellij/testFramework/fixtures/LightJavaCodeInsightFixtureTestCase.java

@@ -90,6 +90,7 @@ public abstract class LightJavaCodeInsightFixtureTestCase extends UsefulTestCase
   public static final @NotNull LightProjectDescriptor JAVA_19 = new ProjectDescriptor(LanguageLevel.JDK_19);
   public static final @NotNull LightProjectDescriptor JAVA_20 = new ProjectDescriptor(LanguageLevel.JDK_20_PREVIEW);
   public static final @NotNull LightProjectDescriptor JAVA_21 = new ProjectDescriptor(LanguageLevel.JDK_21_PREVIEW);
+  public static final @NotNull LightProjectDescriptor JAVA_22 = new ProjectDescriptor(LanguageLevel.JDK_22_PREVIEW);
   public static final @NotNull LightProjectDescriptor JAVA_X = new ProjectDescriptor(LanguageLevel.JDK_X);
 
   public static final @NotNull LightProjectDescriptor JAVA_LATEST = new ProjectDescriptor(LanguageLevel.HIGHEST) {