replacing infinite while loop with do-while doesn't need 'if'

plugins/IntentionPowerPak/src/com/siyeh/ipp/whileloop/ReplaceWhileLoopWithDoWhileLoopIntention.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 Bas Leijdekkers
+ * Copyright 2006-2013 Bas Leijdekkers
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,9 +16,10 @@
 package com.siyeh.ipp.whileloop;
 
 import com.intellij.psi.*;
-import com.intellij.util.IncorrectOperationException;
+import com.siyeh.ig.psiutils.BoolUtils;
 import com.siyeh.ipp.base.Intention;
 import com.siyeh.ipp.base.PsiElementPredicate;
+import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 
 public class ReplaceWhileLoopWithDoWhileLoopIntention extends Intention {
@@ -28,20 +29,22 @@ public class ReplaceWhileLoopWithDoWhileLoopIntention extends Intention {
     return new WhileLoopPredicate();
   }
 
-  protected void processIntention(@NotNull PsiElement element)
-    throws IncorrectOperationException {
-    final PsiWhileStatement whileStatement =
-      (PsiWhileStatement)element.getParent();
+  protected void processIntention(@NotNull PsiElement element) {
+    final PsiWhileStatement whileStatement = (PsiWhileStatement)element.getParent();
     if (whileStatement == null) {
       return;
     }
     final PsiStatement body = whileStatement.getBody();
-    final StringBuilder doWhileStatementText = new StringBuilder("if(");
     final PsiExpression condition = whileStatement.getCondition();
-    if (condition != null) {
-      doWhileStatementText.append(condition.getText());
+    final boolean infiniteLoop = BoolUtils.isTrue(condition);
+    @NonNls final StringBuilder doWhileStatementText = new StringBuilder();
+    if (!infiniteLoop) {
+      doWhileStatementText.append("if(");
+      if (condition != null) {
+        doWhileStatementText.append(condition.getText());
+      }
+      doWhileStatementText.append(") {\n");
     }
-    doWhileStatementText.append(") {\n");
     if (body instanceof PsiBlockStatement) {
       doWhileStatementText.append("do {");
       final PsiBlockStatement blockStatement = (PsiBlockStatement)body;
@@ -56,13 +59,16 @@ public class ReplaceWhileLoopWithDoWhileLoopIntention extends Intention {
       doWhileStatementText.append('}');
     }
     else if (body != null) {
-      doWhileStatementText.append(body.getText());
+      doWhileStatementText.append("do ").append(body.getText()).append('\n');
     }
     doWhileStatementText.append("while(");
     if (condition != null) {
       doWhileStatementText.append(condition.getText());
     }
-    doWhileStatementText.append(");\n}");
+    doWhileStatementText.append(");");
+    if (!infiniteLoop) {
+      doWhileStatementText.append("\n}");
+    }
     replaceStatement(doWhileStatementText.toString(), whileStatement);
   }
 }

plugins/IntentionPowerPak/test/com/siyeh/ipp/whileloop/replace_while_with_do_while_loop/InfiniteLoop.java

@@ -0,0 +1,10 @@
+package com.siyeh.ipp.whileloop.replace_while_with_do_while_loop;
+
+class InfiniteLoop {
+
+  void m() {
+    while<caret>((true)) {
+      System.out.println(1);
+    }
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/whileloop/replace_while_with_do_while_loop/InfiniteLoop_after.java

@@ -0,0 +1,10 @@
+package com.siyeh.ipp.whileloop.replace_while_with_do_while_loop;
+
+class InfiniteLoop {
+
+  void m() {
+      do {
+          System.out.println(1);
+      } while ((true));
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/whileloop/replace_while_with_do_while_loop/NoBraces.java

@@ -0,0 +1,9 @@
+class NoBraces {
+  void m() {
+    while<caret>(b()) System.out.println();
+  }
+
+  boolean b() {
+    return true;
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/whileloop/replace_while_with_do_while_loop/NoBraces_after.java

@@ -0,0 +1,12 @@
+class NoBraces {
+  void m() {
+      if (b()) {
+          do System.out.println();
+          while (b());
+      }
+  }
+
+  boolean b() {
+    return true;
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/whileloop/replace_while_with_do_while_loop/Regular.java

@@ -0,0 +1,14 @@
+package com.siyeh.ipp.whileloop.replace_while_with_do_while_loop;
+
+class Regular {
+
+  void m() {
+    <caret>while(b()) {
+      System.out.println(1);
+    }
+  }
+
+  boolean b() {
+    return true;
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/whileloop/replace_while_with_do_while_loop/Regular_after.java

@@ -0,0 +1,16 @@
+package com.siyeh.ipp.whileloop.replace_while_with_do_while_loop;
+
+class Regular {
+
+  void m() {
+      if (b()) {
+          do {
+              System.out.println(1);
+          } while (b());
+      }
+  }
+
+  boolean b() {
+    return true;
+  }
+}

plugins/IntentionPowerPak/testSrc/com/siyeh/ipp/whileloop/ReplaceWhileLoopWithDoWhileLoopIntentionTest.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2000-2013 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.siyeh.ipp.whileloop;
+
+import com.siyeh.IntentionPowerPackBundle;
+import com.siyeh.ipp.IPPTestCase;
+
+/**
+ * @author Bas Leijdekkers
+ */
+public class ReplaceWhileLoopWithDoWhileLoopIntentionTest extends IPPTestCase {
+
+  public void testInfiniteLoop() { doTest(); }
+  public void testRegular() { doTest(); }
+  public void testNoBraces() { doTest(); }
+
+  @Override
+  protected String getRelativePath() {
+    return "whileloop/replace_while_with_do_while_loop";
+  }
+
+  @Override
+  protected String getIntentionName() {
+    return IntentionPowerPackBundle.message("replace.while.loop.with.do.while.loop.intention.name");
+  }
+}