Integrate EXTRACT_METHOD refactoring into the server.

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/refactoring/extract_method.dart';
@@ skipping 358 matching lines @@
   int v2 = 2;
 // start
   int a = v1 + v2; // marker
 // end
 }
 ''');
     _createRefactoringForStartEndComments();
     // update parameters
     return refactoring.checkInitialConditions().then((_) {
       {
-        var parameters = refactoring.parameters.toList();
+        var 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() {
     indexTestUnit('''
 main() {
   int v1 = 1;
   int v2 = 2;
 // start
   int a = v1 + v2; // marker
 // end
 }
 ''');
     _createRefactoringForStartEndComments();
     // update parameters
     return refactoring.checkInitialConditions().then((_) {
       {
-        var parameters = refactoring.parameters.toList();
+        var 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_selectionEndsInSomeNode() {
@@ skipping 1142 matching lines @@
   int v2 = 2;
   int v3 = 3;
   int a = v1 + v2 + v1; // marker
   int b = v2 + v3 + v2;
 }
 ''');
     _createRefactoringForString('v1 + v2 + v1');
     // apply refactoring
     return refactoring.checkInitialConditions().then((_) {
       {
-        var parameters = refactoring.parameters.toList();
+        var parameters = _getParametersCopy();
         expect(parameters, hasLength(2));
         expect(parameters[0].name, 'v1');
         expect(parameters[1].name, 'v2');
         parameters[0].name = 'par1';
         parameters[1].name = 'param2';
         refactoring.parameters = parameters;
       }
       return assertRefactoringFinalConditionsOK().then((_) {
         refactoring.createGetter = false;
         return _assertRefactoringChange('''
@@ skipping 18 matching lines @@
   int v2 = 2;
   int v3 = 3;
   int a = v1 + v2; // marker
   int b = v2 + v3;
 }
 ''');
     _createRefactoringForString('v1 + v2');
     // apply refactoring
     return refactoring.checkInitialConditions().then((_) {
       {
-        var parameters = refactoring.parameters.toList();
+        var parameters = _getParametersCopy();
         expect(parameters, hasLength(2));
         expect(parameters[0].name, 'v1');
         expect(parameters[1].name, 'v2');
         var parameter = parameters.removeAt(1);
         parameters.insert(0, parameter);
         refactoring.parameters = parameters;
       }
       return assertRefactoringFinalConditionsOK().then((_) {
         refactoring.createGetter = false;
         return _assertRefactoringChange('''
@@ skipping 40 matching lines @@
   int v1 = 1;
   int v2 = 2;
   int v3 = 3;
   int a = v1 + v2 + v3;
 }
 ''');
     _createRefactoringForString('v1 + v2 + v3');
     // apply refactoring
     return refactoring.checkInitialConditions().then((_) {
       {
-        var parameters = refactoring.parameters.toList();
+        var parameters = _getParametersCopy();
         expect(parameters, hasLength(3));
         expect(parameters[0].name, 'v1');
         expect(parameters[1].name, 'v2');
         expect(parameters[2].name, 'v3');
         parameters[0].type = 'num';
         parameters[1].type = 'dynamic';
         parameters[2].type = '';
         refactoring.parameters = parameters;
       }
       return assertRefactoringFinalConditionsOK().then((_) {
@@ skipping 619 matching lines @@
     int offset = findOffset(search);
     int length = search.length;
     _createRefactoring(offset, length);
   }
 
   void _createRefactoringWithSuffix(String selectionSearch, String suffix) {
     int offset = findOffset(selectionSearch + suffix);
     int length = selectionSearch.length;
     _createRefactoring(offset, length);
   }
+
+  /**
+   * 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();
+  }
 }