extract method: null checks should not miss final modifiers ( IDEA-55515 )

java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java

@@ -636,11 +636,7 @@ public class ExtractMethodProcessor implements MatchProvider {
       if (myNullConditionalCheck) {
         final String varName = myOutputVariable.getName();
         if (isDeclaredInside(myOutputVariable)) {
-          PsiDeclarationStatement statement = (PsiDeclarationStatement)myElementFactory
-            .createStatementFromText(myOutputVariable.getType().getCanonicalText() + " " + varName + "=x;", null);
-          statement = (PsiDeclarationStatement)addToMethodCallLocation(statement);
-          myMethodCall =
-            (PsiMethodCallExpression)((PsiLocalVariable)statement.getDeclaredElements()[0]).getInitializer().replace(myMethodCall);
+          declareVariableAtMethodCallLocation(varName);
         }
         else {
           PsiExpressionStatement assignmentExpression =
@@ -676,12 +672,7 @@ public class ExtractMethodProcessor implements MatchProvider {
           myMethodCall = (PsiMethodCallExpression)assignment.getRExpression().replace(myMethodCall);
         }
         else {
-          PsiDeclarationStatement statement =
-            myElementFactory.createVariableDeclarationStatement(name, myOutputVariable.getType(), myMethodCall);
-          statement = (PsiDeclarationStatement)addToMethodCallLocation(statement);
-          PsiVariable var = (PsiVariable)statement.getDeclaredElements()[0];
-          myMethodCall = (PsiMethodCallExpression)var.getInitializer();
-          var.getModifierList().replace(myOutputVariable.getModifierList());
+          declareVariableAtMethodCallLocation(name);
         }
       }
       else if (myHasReturnStatementOutput) {
@@ -737,6 +728,15 @@ public class ExtractMethodProcessor implements MatchProvider {
 
   }
 
+  private void declareVariableAtMethodCallLocation(String name) {
+    PsiDeclarationStatement statement =
+      myElementFactory.createVariableDeclarationStatement(name, myOutputVariable.getType(), myMethodCall);
+    statement = (PsiDeclarationStatement)addToMethodCallLocation(statement);
+    PsiVariable var = (PsiVariable)statement.getDeclaredElements()[0];
+    myMethodCall = (PsiMethodCallExpression)var.getInitializer();
+    var.getModifierList().replace(myOutputVariable.getModifierList());
+  }
+
   private void adjustFinalParameters(final PsiMethod method) throws IncorrectOperationException {
     final IncorrectOperationException[] exc = new IncorrectOperationException[1];
     exc[0] = null;

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

@@ -0,0 +1,13 @@
+class Test {
+  void foo() {
+    <selection>final String str = "";
+    if (str == "") {
+      return;
+    }</selection>
+    new Runnable() {
+      public void run() {
+        System.out.println(str);
+      }
+    }
+  }
+}

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

@@ -0,0 +1,18 @@
+class Test {
+  void foo() {
+      final String str = newMethod();
+    new Runnable() {
+      public void run() {
+        System.out.println(str);
+      }
+    }
+  }
+
+    private String newMethod() {
+        final String str = "";
+        if (str == "") {
+          return;
+        }
+        return str;
+    }
+}

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

@@ -400,6 +400,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doTest();
   }
 
+  public void testNullableCheckDontMissFinal() throws Exception {
+    doTest();
+  }
+
   public void testSimpleArrayAccess() throws Exception {
     doTest();
   }