extract method: detect used lambda params in selection (IDEA-91345)

java/java-impl/src/com/intellij/psi/controlFlow/LocalsControlFlowPolicy.java

@@ -40,13 +40,14 @@ public class LocalsControlFlowPolicy implements ControlFlowPolicy {
 
   @Nullable
   private PsiVariable checkCodeFragment(PsiElement refElement) {
-    PsiElement codeFragement;
-    if (refElement instanceof PsiParameter
-      && ((PsiParameter)refElement).getDeclarationScope() instanceof PsiMethod){
-      codeFragement = ((PsiMethod)((PsiParameter)refElement).getDeclarationScope()).getBody();
-    }
-    else{
-      codeFragement = ControlFlowUtil.findCodeFragment(refElement);
+    PsiElement codeFragement = ControlFlowUtil.findCodeFragment(refElement);
+    if (refElement instanceof PsiParameter) {
+      final PsiElement declarationScope = ((PsiParameter)refElement).getDeclarationScope();
+      if (declarationScope instanceof PsiMethod){
+        codeFragement = ((PsiMethod)declarationScope).getBody();
+      } else if (declarationScope instanceof PsiLambdaExpression) {
+        codeFragement = ((PsiLambdaExpression)declarationScope).getBody();
+      }
     }
     if (codeFragement == null) return null;
     if (myCodeFragment.getContainingFile() == codeFragement.getContainingFile() && //In order for jsp includes to work

java/java-tests/testData/refactoring/extractMethod/OneLineLambda.java

@@ -0,0 +1,5 @@
+class Test {
+  public void foo() {
+    Comparable<String> c = o -> <selection>o.indexOf("foo")</selection>;
+  }
+}

java/java-tests/testData/refactoring/extractMethod/OneLineLambda_after.java

@@ -0,0 +1,9 @@
+class Test {
+  public void foo() {
+    Comparable<String> c = o -> newMethod(o);
+  }
+
+    private int newMethod(String o) {
+        return o.indexOf("foo");
+    }
+}

java/java-tests/testSrc/com/intellij/refactoring/ExtractMethodTest.java

@@ -540,6 +540,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doTest();
   }
 
+  public void testOneLineLambda() throws Exception {
+    doTest();
+  }
+
   private void doTestDisabledParam() throws PrepareFailedException {
     final CodeStyleSettings settings = CodeStyleSettingsManager.getSettings(getProject());
     settings.ELSE_ON_NEW_LINE = true;