Issue 22988. Improve checking for conflicts between parameters and local elements during extracting…

pkg/analysis_server/test/services/refactoring/extract_method_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.services.refactoring.extract_method;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/correction/status.dart';
@@ skipping 366 matching lines @@
     {
       List<RefactoringMethodParameter> parameters = _getParametersCopy();
       expect(parameters, hasLength(2));
       parameters[0].name = 'dup';
       parameters[1].name = 'dup';
       refactoring.parameters = parameters;
     }
     return _assertFinalConditionsError("Parameter 'dup' already exists");
   }
 
-  test_bad_parameterName_inUse() async {
+  test_bad_parameterName_inUse_function() async {
     indexTestUnit('''
 main() {
   int v1 = 1;
+  int v2 = 2;
+// start
+  f(v1, v2);
+// end
+}
+f(a, b) {}
+''');
+    _createRefactoringForStartEndComments();
+    // update parameters
+    await refactoring.checkInitialConditions();
+    {
+      List<RefactoringMethodParameter> parameters = _getParametersCopy();
+      expect(parameters, hasLength(2));
+      parameters[0].name = 'f';
+      refactoring.parameters = parameters;
+    }
+    return _assertFinalConditionsError(
+        "'f' is already used as a name in the selected code");
+  }
+
+  test_bad_parameterName_inUse_localVariable() async {
+    indexTestUnit('''
+main() {
+  int v1 = 1;
   int v2 = 2;
 // start
   int a = v1 + v2; // marker
 // end
 }
 ''');
     _createRefactoringForStartEndComments();
     // update parameters
     await refactoring.checkInitialConditions();
     {
       List<RefactoringMethodParameter> parameters = _getParametersCopy();
       expect(parameters, hasLength(2));
       parameters[0].name = 'a';
       refactoring.parameters = parameters;
     }
     return _assertFinalConditionsError(
         "'a' is already used as a name in the selected code");
   }
 
+  test_bad_parameterName_inUse_method() async {
+    indexTestUnit('''
+class A {
+  main() {
+    int v1 = 1;
+    int v2 = 2;
+  // start
+    m(v1, v2);
+  // end
+  }
+  m(a, b) {}
+}
+''');
+    _createRefactoringForStartEndComments();
+    // update parameters
+    await refactoring.checkInitialConditions();
+    {
+      List<RefactoringMethodParameter> parameters = _getParametersCopy();
+      expect(parameters, hasLength(2));
+      parameters[0].name = 'm';
+      refactoring.parameters = parameters;
+    }
+    return _assertFinalConditionsError(
+        "'m' is already used as a name in the selected code");
+  }
+
   test_bad_selectionEndsInSomeNode() {
     indexTestUnit('''
 main() {
 // start
   print(0);
   print(1);
 // end
 }
 ''');
     _createRefactoringForStartEndString('print(0', 'rint(1)');
@@ skipping 1786 matching lines @@
   res(v);
 // end
 }
 
 void res(Future<int> v) {
   print(v);
 }
 ''');
   }
 
+  test_statements_parameters_noLocalVariableConflict() async {
+    indexTestUnit('''
+int f(int x) {
+  int y = x + 1;
+// start
+  if (y % 2 == 0) {
+    int y = x + 2;
+    return y;
+  } else {
+    return y;
+  }
+// end
+}
+''');
+    _createRefactoringForStartEndComments();
+    await assertRefactoringConditionsOK();
+  }
+
   test_statements_return_last() {
     indexTestUnit('''
 main() {
 // start
   int v = 5;
   return v + 1;
 // end
 }
 ''');
     _createRefactoringForStartEndComments();
@@ skipping 271 matching lines @@
    * Returns a deep copy of [refactoring] parameters.
    * There was a bug masked by updating parameter instances shared between the
    * refactoring and the test.
    */
   List<RefactoringMethodParameter> _getParametersCopy() {
     return refactoring.parameters.map((p) {
       return new RefactoringMethodParameter(p.kind, p.type, p.name, id: p.id);
     }).toList();
   }
 }