IG/IPP: fix extract increment/decrement to separate statement (IDEA-203698)

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/assignment/IncrementDecrementUsedAsExpressionInspection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2015 Dave Griffith, Bas Leijdekkers
+ * Copyright 2003-2018 Dave Griffith, Bas Leijdekkers
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,6 +28,7 @@ import com.siyeh.ig.BaseInspection;
 import com.siyeh.ig.BaseInspectionVisitor;
 import com.siyeh.ig.InspectionGadgetsFix;
 import com.siyeh.ig.PsiReplacementUtil;
+import com.siyeh.ig.psiutils.ExpressionUtils;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -143,24 +144,27 @@ public class IncrementDecrementUsedAsExpressionInspection
       return;
     }
     final Project project = element.getProject();
-    final PsiElementFactory factory =
-      JavaPsiFacade.getInstance(project).getElementFactory();
+    final PsiElementFactory factory = JavaPsiFacade.getInstance(project).getElementFactory();
     final String newStatementText = element.getText() + ';';
     final String operandText = operand.getText();
-    if (parent instanceof PsiIfStatement ||
-        parent instanceof PsiLoopStatement) {
+    if (parent instanceof PsiIfStatement || parent instanceof PsiLoopStatement || parent instanceof PsiSwitchLabeledRuleStatement) {
       // need to add braces because
       // in/decrement is inside braceless control statement body
       final StringBuilder text = new StringBuilder();
       text.append('{');
-      final String elementText =
-        PsiReplacementUtil.getElementText(statement, element, operandText);
+      final String elementText = PsiReplacementUtil.getElementText(statement, element, operandText);
       if (element instanceof PsiPostfixExpression) {
+        if (parent instanceof PsiSwitchLabeledRuleStatement) {
+          text.append("break ");
+        }
         text.append(elementText);
         text.append(newStatementText);
       }
       else {
         text.append(newStatementText);
+        if (parent instanceof PsiSwitchLabeledRuleStatement) {
+          text.append("break ");
+        }
         text.append(elementText);
       }
       text.append('}');
@@ -323,16 +327,11 @@ public class IncrementDecrementUsedAsExpressionInspection
   }
 
   public static boolean isSuitableForReplacement(@NotNull PsiUnaryExpression expression) {
-    final PsiElement parent = expression.getParent();
-    if (parent instanceof PsiExpressionStatement ||
-        (parent instanceof PsiExpressionList &&
-         parent.getParent() instanceof
-           PsiExpressionListStatement)) {
+    if (ExpressionUtils.isVoidContext(expression)) {
       return false;
     }
     final IElementType tokenType = expression.getOperationTokenType();
-    if (!tokenType.equals(JavaTokenType.PLUSPLUS) &&
-        !tokenType.equals(JavaTokenType.MINUSMINUS)) {
+    if (!tokenType.equals(JavaTokenType.PLUSPLUS) && !tokenType.equals(JavaTokenType.MINUSMINUS)) {
       return false;
     }
     return PsiTreeUtil.getParentOfType(expression, PsiStatement.class) != null;
@@ -347,8 +346,7 @@ public class IncrementDecrementUsedAsExpressionInspection
     extends BaseInspectionVisitor {
 
     @Override
-    public void visitUnaryExpression(
-      @NotNull PsiUnaryExpression expression) {
+    public void visitUnaryExpression(@NotNull PsiUnaryExpression expression) {
       super.visitUnaryExpression(expression);
 
       if (isSuitableForReplacement(expression)) {

plugins/IntentionPowerPak/test/com/siyeh/ipp/extractIncrement/SwitchExpression.java

@@ -0,0 +1,7 @@
+class Main {
+  int test(int i) {
+    return switch(i) {
+      default -> ++<caret>i;
+    };
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/extractIncrement/SwitchExpression_after.java

@@ -0,0 +1,10 @@
+class Main {
+  int test(int i) {
+    return switch(i) {
+      default -> {
+          ++i;
+          break i;
+      }
+    };
+  }
+}

plugins/IntentionPowerPak/testSrc/com/siyeh/ipp/extractIncrement/ExtractIncrementAndDecrementTest.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.siyeh.ipp.extractIncrement;
 
 import com.intellij.codeInsight.intention.IntentionAction;
@@ -34,6 +20,8 @@ public class ExtractIncrementAndDecrementTest extends IPPTestCase {
 
   public void testPrefixIncrement() {doExtractTest("++");}
 
+  public void testSwitchExpression() {doExtractTest("++");}
+
   public void testSingleDoWhileBody() {doExtractTest("++");}
 
   public void testDecrementInForUpdate() {doNegativeTest("--");}