switch -> if: fix comments line breaks (IDEA-195383)

java/java-impl/src/com/intellij/codeInsight/daemon/impl/quickfix/ConvertSwitchToIfIntention.java

@@ -280,6 +280,8 @@ public class ConvertSwitchToIfIntention implements IntentionAction {
         out.append(variable.getType().getCanonicalText()).append(' ').append(variable.getName()).append(';');
       }
     }
+
+    boolean addLineBreak = true;
     for (PsiElement bodyStatement : bodyStatements) {
       if (bodyStatement instanceof PsiBlockStatement) {
         final PsiBlockStatement blockStatement = (PsiBlockStatement)bodyStatement;
@@ -289,21 +291,25 @@ public class ConvertSwitchToIfIntention implements IntentionAction {
         }
       }
       else {
-        appendElement(bodyStatement, out, commentTracker);
+        addLineBreak = appendElement(bodyStatement, out, commentTracker);
       }
     }
-    out.append("\n}");
+    if (addLineBreak) {
+      out.append("\n");
+    }
+    out.append("}");
   }
 
-  private static void appendElement(PsiElement element, @NonNls StringBuilder out, CommentTracker commentTracker) {
-    if (element instanceof PsiWhiteSpace) return;
+  private static boolean appendElement(PsiElement element, @NonNls StringBuilder out, CommentTracker commentTracker) {
     if (element instanceof PsiBreakStatement) {
       final PsiBreakStatement breakStatement = (PsiBreakStatement)element;
       final PsiIdentifier identifier = breakStatement.getLabelIdentifier();
       if (identifier == null) {
-        return;
+        return false;
       }
     }
     out.append(commentTracker.text(element));
+
+    return true;
   }
 }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/convertSwitchToIf/afterComment.java

@@ -0,0 +1,11 @@
+// "Replace 'switch' with 'if'" "true"
+class X {
+  void test(int i) {
+      if (i == 1) {//foo
+          if (Math.random() > 0.5) {
+              System.out.println("Hello");
+          }
+      }
+    }
+
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/convertSwitchToIf/beforeComment.java

@@ -0,0 +1,13 @@
+// "Replace 'switch' with 'if'" "true"
+class X {
+  void test(int i) {
+    <caret>switch (i) {
+        case 1:
+            //foo
+            if (Math.random() > 0.5) {
+                System.out.println("Hello");
+            }
+        }
+    }
+
+}