From 6edc546e656f88cdaaa355ca8dd598cb28997c36 Mon Sep 17 00:00:00 2001
From: anna <Anna.Kozlova@jetbrains.com>
Date: Wed, 20 Feb 2013 21:28:18 +0100
Subject: [PATCH] lambda: void compatibility guess

---
 .../src/com/intellij/psi/LambdaHighlightingUtil.java |  2 +-
 .../lambda/highlighting/VoidCompatibility.java       | 12 ++++++++++++
 .../daemon/lambda/LambdaHighlightingTest.java        |  4 ++++
 3 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/VoidCompatibility.java

diff --git a/java/java-psi-api/src/com/intellij/psi/LambdaHighlightingUtil.java b/java/java-psi-api/src/com/intellij/psi/LambdaHighlightingUtil.java
index e8b8e1d68a70..50030d468571 100644
--- a/java/java-psi-api/src/com/intellij/psi/LambdaHighlightingUtil.java
+++ b/java/java-psi-api/src/com/intellij/psi/LambdaHighlightingUtil.java
@@ -40,7 +40,7 @@ public class LambdaHighlightingUtil {
       final PsiElement body = lambdaExpression.getBody();
       if (body instanceof PsiCodeBlock) {
         if (!LambdaUtil.getReturnExpressions(lambdaExpression).isEmpty()) return "Unexpected return value";
-      } else if (body instanceof PsiExpression) {
+      } else if (body instanceof PsiReferenceExpression || body instanceof PsiLiteralExpression) {
         final PsiType type = ((PsiExpression)body).getType();
         if (type != PsiType.VOID) {
           return "Incompatible return type " + (type == PsiType.NULL || type == null ? "<null>" : type.getPresentableText()) +" in lambda expression";
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/VoidCompatibility.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/VoidCompatibility.java
new file mode 100644
index 000000000000..88208b911a5d
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/VoidCompatibility.java
@@ -0,0 +1,12 @@
+public class Main {
+    interface I<T> {
+        void m(T t);
+    }
+
+    {
+        String s = "";
+        I<Object> arr1 = <error descr="Incompatible return type String in lambda expression">(t) -> s</error>;
+        I<Object> arr2 = (t) -> s.toString();
+    }
+
+}
diff --git a/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaHighlightingTest.java b/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaHighlightingTest.java
index 42b1aa0fda52..fb83818521de 100644
--- a/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaHighlightingTest.java
+++ b/java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaHighlightingTest.java
@@ -220,6 +220,10 @@ public class LambdaHighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testVoidCompatibility() throws Exception {
+    doTest();
+  }
+
   private void doTest() throws Exception {
     doTest(false);
   }