Java inspection: Returned back RemoveRedundantElseAction intention, because it turns out it's useful in some cases (IDEA-157727)

2026-09-18 09:34:34 +07:00 · 2016-07-20 18:50:32 +03:00
parent ec05aa8b85
commit b525e80a87
10 changed files with 229 additions and 0 deletions
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2000-2009 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.
+ */
+package com.intellij.codeInsight.daemon.impl.quickfix;
+
+import com.intellij.codeInsight.FileModificationService;
+import com.intellij.codeInsight.daemon.QuickFixBundle;
+import com.intellij.codeInsight.intention.PsiElementBaseIntentionAction;
+import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.project.Project;
+import com.intellij.psi.*;
+import com.intellij.psi.controlFlow.*;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.util.BitUtil;
+import com.intellij.util.IncorrectOperationException;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * @author ven
+ */
+public class RemoveRedundantElseAction extends PsiElementBaseIntentionAction {
+  private static final Logger LOG = Logger.getInstance("#com.intellij.codeInsight.daemon.impl.quickfix.RemoveRedundantElseAction");
+
+  @Override
+  @NotNull
+  public String getText() {
+    return QuickFixBundle.message("remove.redundant.else.fix");
+  }
+
+  @Override
+  @NotNull
+  public String getFamilyName() {
+    return QuickFixBundle.message("remove.redundant.else.fix");
+  }
+
+  @Override
+  public boolean isAvailable(@NotNull Project project, Editor editor, @NotNull PsiElement element) {
+    if (element instanceof PsiKeyword &&
+        element.getParent() instanceof PsiIfStatement &&
+        PsiKeyword.ELSE.equals(element.getText())) {
+      PsiIfStatement ifStatement = (PsiIfStatement)element.getParent();
+      if (ifStatement.getElseBranch() == null) return false;
+      PsiStatement thenBranch = ifStatement.getThenBranch();
+      if (thenBranch == null) return false;
+      PsiElement block = PsiTreeUtil.getParentOfType(ifStatement, PsiCodeBlock.class);
+      if (block != null) {
+        while (cantCompleteNormally(thenBranch, block)) {
+          thenBranch = getPrevThenBranch(thenBranch);
+          if (thenBranch == null) return true;
+        }
+        return false;
+      }
+    }
+    return false;
+  }
+
+  @Nullable
+  private static PsiStatement getPrevThenBranch(@NotNull PsiElement thenBranch) {
+    final PsiElement ifStatement = thenBranch.getParent();
+    final PsiElement parent = ifStatement.getParent();
+    if (parent instanceof PsiIfStatement && ((PsiIfStatement)parent).getElseBranch() == ifStatement) {
+      return ((PsiIfStatement)parent).getThenBranch();
+    }
+    return null;
+  }
+
+  private static boolean cantCompleteNormally(@NotNull PsiStatement thenBranch, PsiElement block) {
+    try {
+      ControlFlow controlFlow = ControlFlowFactory.getInstance(thenBranch.getProject()).getControlFlow(block, LocalsOrMyInstanceFieldsControlFlowPolicy.getInstance());
+      int startOffset = controlFlow.getStartOffset(thenBranch);
+      int endOffset = controlFlow.getEndOffset(thenBranch);
+      return startOffset != -1 && endOffset != -1 && !BitUtil.isSet(ControlFlowUtil.getCompletionReasons(controlFlow, startOffset, endOffset), ControlFlowUtil.NORMAL_COMPLETION_REASON);
+    }
+    catch (AnalysisCanceledException e) {
+      return false;
+    }
+  }
+
+  @Override
+  public void invoke(@NotNull Project project, Editor editor, @NotNull PsiElement element) throws IncorrectOperationException {
+    if (!FileModificationService.getInstance().preparePsiElementForWrite(element)) return;
+    PsiIfStatement ifStatement = (PsiIfStatement)element.getParent();
+    LOG.assertTrue(ifStatement != null && ifStatement.getElseBranch() != null);
+    PsiStatement elseBranch = ifStatement.getElseBranch();
+    if (elseBranch instanceof PsiBlockStatement) {
+      PsiElement[] statements = ((PsiBlockStatement)elseBranch).getCodeBlock().getStatements();
+      if (statements.length > 0) {
+        ifStatement.getParent().addRangeAfter(statements[0], statements[statements.length-1], ifStatement);
+      }
+    } else {
+      ifStatement.getParent().addAfter(elseBranch, ifStatement);
+    }
+    ifStatement.getElseBranch().delete();
+  }
+}
@@ -0,0 +1,13 @@
+// "Remove redundant 'else'" "true"
+class a {
+  void foo() {
+    int a = 0;
+    int b = 0;
+    if (a != b) {
+      return;
+    }
+      a = b;
+      a++;
+  }
+}
+
@@ -0,0 +1,14 @@
+// "Remove redundant 'else'" "true"
+class a {
+  void foo() {
+    int a = 0;
+    int b = 0;
+    if (a != b) {
+      return;
+    } e<caret>lse {
+      a = b;
+    }
+    a++;
+  }
+}
+
@@ -0,0 +1,15 @@
+// "Remove redundant 'else'" "false"
+import java.io.IOException;
+class a {
+  void foo(boolean condition) throws IOException{
+    if (condition) {
+      tMethod();
+    }
+    e<caret>lse {
+      System.out.println("else");
+    }
+  }
+
+  void tMethod() throws IOException {}
+}
+
@@ -0,0 +1,17 @@
+// "Remove redundant 'else'" "false"
+class a {
+  void foo() {
+    int a = 0;
+    int b = 0;
+    if (a != b) {
+      a = 10;
+    } else if (a + 1 == b) {
+      return;
+    }
+    e<caret>lse {
+      a = b;
+    }
+    a++;
+  }
+}
+
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2000-2010 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.
+ */
+package com.intellij.codeInsight.daemon.quickFix;
+
+/**
+ * User: anna
+ * Date: Aug 30, 2010
+ */
+public class RemoveRedundantElseActionTest extends LightQuickFixParameterizedTestCase {
+
+  public void test() throws Exception { doAllTests(); }
+
+  @Override
+  protected String getBasePath() {
+    return "/codeInsight/daemonCodeAnalyzer/quickFix/removeRedundantElse";
+  }
+
+}
+
@@ -0,0 +1,8 @@
+public class X {
+  void f(int i) {
+    if (i==0) {
+      return;
+    }
+    int j = 0;
+  }
+}
@@ -0,0 +1,10 @@
+public class X {
+  void f(int i) {
+    if (i==0) {
+      return;
+    }
+    <spot>else</spot> {
+      int j = 0;
+    }
+  }
+}
@@ -0,0 +1,7 @@
+<html>
+<body>
+This intention detaches <b>else</b> clause from the <b>if</b> statement,
+if corresponding <b>then</b> clause never completes normally.
+
+</body>
+</html>
@@ -832,6 +832,10 @@
      <className>com.intellij.codeInsight.intention.impl.ExtractIfConditionAction</className>
      <category>Java/Control Flow</category>
    </intentionAction>
+    <intentionAction>
+      <className>com.intellij.codeInsight.daemon.impl.quickfix.RemoveRedundantElseAction</className>
+      <category>Java/Control Flow</category>
+    </intentionAction>
    <intentionAction>
      <className>com.intellij.codeInsight.intention.impl.AddNotNullAnnotationIntention</className>
      <category>Java/Annotations</category>