From c98d7f0c5e47a0ef6cb717b8bf9f4de652424e4b Mon Sep 17 00:00:00 2001
From: Anna Kozlova <anna.kozlova@jetbrains.com>
Date: Wed, 13 Aug 2014 18:37:05 +0400
Subject: [PATCH] lambda completion: reformat, ensure unique names
 (IDEA-128567)

---
 .../completion/LambdaCompletionProvider.java  | 22 ++++++++++++++-----
 .../InLambdaPositionSameNames-out.java        | 10 +++++++++
 .../smartType/InLambdaPositionSameNames.java  | 10 +++++++++
 .../completion/SmartType18CompletionTest.java |  3 +++
 4 files changed, 40 insertions(+), 5 deletions(-)
 create mode 100644 java/java-tests/testData/codeInsight/completion/smartType/InLambdaPositionSameNames-out.java
 create mode 100644 java/java-tests/testData/codeInsight/completion/smartType/InLambdaPositionSameNames.java

diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/LambdaCompletionProvider.java b/java/java-impl/src/com/intellij/codeInsight/completion/LambdaCompletionProvider.java
index f169ccd8aa56..4fd7df6c7e2e 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/LambdaCompletionProvider.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/LambdaCompletionProvider.java
@@ -25,6 +25,7 @@ import com.intellij.openapi.editor.EditorModificationUtil;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
+import com.intellij.psi.codeStyle.CodeStyleManager;
 import com.intellij.psi.codeStyle.JavaCodeStyleManager;
 import com.intellij.psi.impl.source.resolve.graphInference.FunctionalInterfaceParameterizationUtil;
 import com.intellij.psi.util.PsiUtil;
@@ -52,18 +53,25 @@ public class LambdaCompletionProvider extends CompletionProvider<CompletionParam
           final Project project = method.getProject();
           final PsiElement originalPosition = parameters.getOriginalPosition();
           final JVMElementFactory jvmElementFactory = originalPosition != null ? JVMElementFactories.getFactory(originalPosition.getLanguage(), project) : null;
+          final JavaCodeStyleManager javaCodeStyleManager = JavaCodeStyleManager.getInstance(project);
           if (jvmElementFactory != null) {
             final PsiSubstitutor substitutor = LambdaUtil.getSubstitutor(method, PsiUtil.resolveGenericsClassInType(functionalInterfaceType));
-            final JavaCodeStyleManager codeStyleManager = JavaCodeStyleManager.getInstance(project);
-            params = GenerateMembersUtil.overriddenParameters(params, jvmElementFactory, codeStyleManager, substitutor, originalPosition);
+            params = GenerateMembersUtil.overriddenParameters(params, jvmElementFactory, javaCodeStyleManager, substitutor, originalPosition);
           }
 
-          final String paramsString = params.length == 1 ? params[0].getName() : "(" + StringUtil.join(params, new Function<PsiParameter, String>() {
+          String paramsString =
+            params.length == 1 ? getParamName(params[0], javaCodeStyleManager, originalPosition) : "(" + StringUtil.join(params, new Function<PsiParameter, String>() {
             @Override
             public String fun(PsiParameter parameter) {
-              return parameter.getName();
+              return getParamName(parameter, javaCodeStyleManager, originalPosition);
             }
-          }, ",") + ")";
+            }, ",") + ")";
+
+          final CodeStyleManager codeStyleManager = CodeStyleManager.getInstance(project);
+          PsiLambdaExpression lambdaExpression = (PsiLambdaExpression)JavaPsiFacade.getElementFactory(project)
+            .createExpressionFromText(paramsString + " -> {}", null);
+          lambdaExpression = (PsiLambdaExpression)codeStyleManager.reformat(lambdaExpression);
+          paramsString = lambdaExpression.getParameterList().getText();
           final LookupElementBuilder builder =
             LookupElementBuilder.create(paramsString).withPresentableText(paramsString + " -> {}").withInsertHandler(new InsertHandler<LookupElement>() {
               @Override
@@ -77,4 +85,8 @@ public class LambdaCompletionProvider extends CompletionProvider<CompletionParam
       }
     }
   }
+
+  private static String getParamName(PsiParameter param, JavaCodeStyleManager javaCodeStyleManager, PsiElement originalPosition) {
+    return javaCodeStyleManager.suggestUniqueVariableName(param.getName(), originalPosition, true);
+  }
 }
diff --git a/java/java-tests/testData/codeInsight/completion/smartType/InLambdaPositionSameNames-out.java b/java/java-tests/testData/codeInsight/completion/smartType/InLambdaPositionSameNames-out.java
new file mode 100644
index 000000000000..48157c4ded2a
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/smartType/InLambdaPositionSameNames-out.java
@@ -0,0 +1,10 @@
+interface I<T> {
+  void m(T t, String s);
+}
+
+class Test {
+  public static void main(String[] args) {
+    String s = "";
+    I<String> i = (s1, s2) -> <caret>
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/codeInsight/completion/smartType/InLambdaPositionSameNames.java b/java/java-tests/testData/codeInsight/completion/smartType/InLambdaPositionSameNames.java
new file mode 100644
index 000000000000..e7adb2ffb758
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/smartType/InLambdaPositionSameNames.java
@@ -0,0 +1,10 @@
+interface I<T> {
+  void m(T t, String s);
+}
+
+class Test {
+  public static void main(String[] args) {
+    String s = "";
+    I<String> i = <caret>
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/codeInsight/completion/SmartType18CompletionTest.java b/java/java-tests/testSrc/com/intellij/codeInsight/completion/SmartType18CompletionTest.java
index d98f0a68b72b..eb3c4c4577b6 100644
--- a/java/java-tests/testSrc/com/intellij/codeInsight/completion/SmartType18CompletionTest.java
+++ b/java/java-tests/testSrc/com/intellij/codeInsight/completion/SmartType18CompletionTest.java
@@ -80,6 +80,9 @@ public class SmartType18CompletionTest extends LightFixtureCompletionTestCase {
   public void testInLambdaPositionNameSubstitution() throws Exception {
     doTest();
   }
+  public void testInLambdaPositionSameNames() throws Exception {
+    doTest();
+  }
 
   public void testConstructorRef() throws Exception {
     doTest(false);