[java] DeleteSwitchLabelFix must produce 'default:' instead of 'case default:'

IDEA-309550

GitOrigin-RevId: 3224934e68d9b0f9008fe7305f0209d3487a7f65

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/fix/DeleteSwitchLabelFix.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// 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.codeInspection.dataFlow.fix;
 
 import com.intellij.codeInsight.daemon.impl.analysis.SwitchBlockHighlightingModel;
@@ -16,6 +16,7 @@ import com.intellij.util.ObjectUtils;
 import com.intellij.util.containers.ContainerUtil;
 import com.siyeh.ig.psiutils.CommentTracker;
 import com.siyeh.ig.psiutils.ControlFlowUtils;
+import com.siyeh.ig.psiutils.SwitchUtils;
 import one.util.streamex.StreamEx;
 import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
@@ -77,7 +78,7 @@ public class DeleteSwitchLabelFix extends LocalQuickFixAndIntentionActionOnPsiEl
     if (label == null) return;
     PsiSwitchBlock block = label.getEnclosingSwitchBlock();
     if (block == null) return;
-    deleteLabelElement(labelElement);
+    deleteLabelElement(project, labelElement);
     if (myAddDefaultIfNecessary) {
       IntentionAction addDefaultFix = SwitchBlockHighlightingModel.createAddDefaultFixIfNecessary(block);
       if (addDefaultFix != null) {
@@ -86,15 +87,27 @@ public class DeleteSwitchLabelFix extends LocalQuickFixAndIntentionActionOnPsiEl
     }
   }
 
-  public static void deleteLabelElement(@NotNull PsiCaseLabelElement labelElement) {
+  public static void deleteLabelElement(@NotNull Project project, @NotNull PsiCaseLabelElement labelElement) {
     PsiSwitchLabelStatementBase label = PsiImplUtil.getSwitchLabel(labelElement);
     if (label == null) return;
     PsiCaseLabelElementList labelElementList = label.getCaseLabelElementList();
-    if (labelElementList != null && labelElementList.getElementCount() == 1) {
-      deleteLabel(label);
-    } else {
-      new CommentTracker().deleteAndRestoreComments(labelElement);
+    if (labelElementList != null) {
+      if (labelElementList.getElementCount() == 1) {
+        deleteLabel(label);
+        return;
+      }
+      else if (labelElementList.getElementCount() == 2) {
+        PsiElement defaultElement = SwitchUtils.findDefaultElement(label);
+        if (defaultElement != null && defaultElement != labelElement) {
+          new CommentTracker().deleteAndRestoreComments(labelElementList);
+          PsiElementFactory factory = PsiElementFactory.getInstance(project);
+          PsiKeyword defaultKeyword = factory.createKeyword(PsiKeyword.DEFAULT);
+          label.getFirstChild().replace(defaultKeyword);
+          return;
+        }
+      }
     }
+    new CommentTracker().deleteAndRestoreComments(labelElement);
   }
 
   public static void deleteLabel(PsiSwitchLabelStatementBase label) {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/deleteSwitchLabel/afterDuplicateNullLabel2.java

@@ -0,0 +1,9 @@
+// "Remove switch label 'null'" "true-preview"
+class X {
+  void test(String s) {
+    switch (s) {
+      case null -> System.out.println("null");
+      default -> System.out.println("null or default");
+    }
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/deleteSwitchLabel/beforeDuplicateNullLabel2.java

@@ -0,0 +1,9 @@
+// "Remove switch label 'null'" "true-preview"
+class X {
+  void test(String s) {
+    switch (s) {
+      case null -> System.out.println("null");
+      case null<caret>, default -> System.out.println("null or default");
+    }
+  }
+}

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/controlflow/UnnecessaryDefaultInspection.java

@@ -22,7 +22,6 @@ import com.intellij.codeInspection.ProblemDescriptor;
 import com.intellij.codeInspection.ProblemHighlightType;
 import com.intellij.codeInspection.dataFlow.fix.DeleteSwitchLabelFix;
 import com.intellij.codeInspection.options.OptPane;
-import com.intellij.codeInspection.ui.SingleCheckboxOptionsPanel;
 import com.intellij.openapi.project.Project;
 import com.intellij.psi.*;
 import com.intellij.psi.controlFlow.*;
@@ -37,7 +36,6 @@ import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import javax.swing.*;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
@@ -45,7 +43,8 @@ import java.util.Set;
 import static com.intellij.codeInsight.daemon.impl.analysis.SwitchBlockHighlightingModel.PatternsInSwitchBlockHighlightingModel.CompletenessResult.COMPLETE_WITHOUT_TOTAL;
 import static com.intellij.codeInspection.ProblemHighlightType.GENERIC_ERROR_OR_WARNING;
 import static com.intellij.codeInspection.ProblemHighlightType.INFORMATION;
-import static com.intellij.codeInspection.options.OptPane.*;
+import static com.intellij.codeInspection.options.OptPane.checkbox;
+import static com.intellij.codeInspection.options.OptPane.pane;
 
 public class UnnecessaryDefaultInspection extends BaseInspection {
 
@@ -81,11 +80,11 @@ public class UnnecessaryDefaultInspection extends BaseInspection {
     @Override
     protected void doFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
       final PsiElement element = descriptor.getPsiElement().getParent();
-      if (element instanceof PsiSwitchLabelStatementBase) {
-        DeleteSwitchLabelFix.deleteLabel((PsiSwitchLabelStatementBase)element);
+      if (element instanceof PsiSwitchLabelStatementBase label) {
+        DeleteSwitchLabelFix.deleteLabel(label);
       }
-      else if (element instanceof PsiDefaultCaseLabelElement) {
-        DeleteSwitchLabelFix.deleteLabelElement((PsiDefaultCaseLabelElement)element);
+      else if (element instanceof PsiDefaultCaseLabelElement defaultElement) {
+        DeleteSwitchLabelFix.deleteLabelElement(project, defaultElement);
       }
     }
   }