unused assignment: check lambda body for unused assignments

java/java-analysis-impl/src/com/intellij/codeInspection/defUse/DefUseInspectionBase.java

@@ -54,6 +54,14 @@ public class DefUseInspectionBase extends BaseJavaBatchLocalInspectionTool {
       public void visitClassInitializer(PsiClassInitializer initializer) {
         checkCodeBlock(initializer.getBody(), holder, isOnTheFly);
       }
+
+      @Override
+      public void visitLambdaExpression(PsiLambdaExpression expression) {
+        PsiElement body = expression.getBody();
+        if (body instanceof PsiCodeBlock) {
+          checkCodeBlock((PsiCodeBlock)body, holder, isOnTheFly);
+        }
+      }
     };
   }
 

java/java-tests/testData/inspection/defUse/AssignmentsInLambdaBody.java

@@ -0,0 +1,7 @@
+class Test {
+  Runnable r = () -> {
+    int i = <warning descr="Variable 'i' initializer '0' is redundant">0</warning>;
+    i = 1;
+    System.out.println(i);
+  };
+}

java/java-tests/testSrc/com/intellij/codeInspection/DefUseTest.java

@@ -53,6 +53,7 @@ public class DefUseTest extends LightCodeInsightFixtureTestCase {
   public void testComplexDoubleTryFinally() { doTest(); }
   public void testComplexTripleTryFinally() { doTest(); }
   public void testComplexQuintipleTryFinally() { doTest(); }
+  public void testAssignmentsInLambdaBody() { doTest(); }
 
   private void doTest() {
     myFixture.enableInspections(new DefUseInspection());