Issue 25253. Improve collecting names that may conflict with the extracted local variable.

pkg/analysis_server/test/services/refactoring/extract_local_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_local;
 
 import 'dart:async';
 import 'dart:convert';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
@@ skipping 18 matching lines @@
   test_checkFinalConditions_sameVariable_after() async {
     indexTestUnit('''
 main() {
   int a = 1 + 2;
   var res;
 }
 ''');
     _createRefactoringForString('1 + 2');
     // conflicting name
     RefactoringStatus status = await refactoring.checkAllConditions();
-    assertRefactoringStatus(status, RefactoringProblemSeverity.WARNING,
-        expectedMessage:
-            "A variable with name 'res' is already defined in the visible scope.");
+    assertRefactoringStatus(status, RefactoringProblemSeverity.ERROR,
+        expectedMessage: "The name 'res' is already used in the scope.");
   }
 
   test_checkFinalConditions_sameVariable_before() async {
     indexTestUnit('''
 main() {
   var res;
   int a = 1 + 2;
 }
 ''');
     _createRefactoringForString('1 + 2');
     // conflicting name
     RefactoringStatus status = await refactoring.checkAllConditions();
-    assertRefactoringStatus(status, RefactoringProblemSeverity.WARNING,
-        expectedMessage:
-            "A variable with name 'res' is already defined in the visible scope.");
+    assertRefactoringStatus(status, RefactoringProblemSeverity.ERROR,
+        expectedMessage: "The name 'res' is already used in the scope.");
   }
 
   test_checkInitialConditions_assignmentLeftHandSize() async {
     indexTestUnit('''
 main() {
   var v = 0;
   v = 1;
 }
 ''');
     _createRefactoringWithSuffix('v', ' = 1;');
@@ skipping 89 matching lines @@
   print(42);
 }
 ''');
     _createRefactoringForString('print');
     // check conditions
     RefactoringStatus status = await refactoring.checkInitialConditions();
     assertRefactoringStatus(status, RefactoringProblemSeverity.FATAL,
         expectedMessage: 'Cannot extract the void expression.');
   }
 
-  test_checkLocalName() {
+  test_checkName() {
     indexTestUnit('''
 main() {
   int a = 1 + 2;
 }
 ''');
     _createRefactoringForString('1 + 2');
     expect(refactoring.refactoringName, 'Extract Local Variable');
     // null
     refactoring.name = null;
     assertRefactoringStatus(
         refactoring.checkName(), RefactoringProblemSeverity.FATAL,
         expectedMessage: "Variable name must not be null.");
     // empty
     refactoring.name = '';
     assertRefactoringStatus(
         refactoring.checkName(), RefactoringProblemSeverity.FATAL,
         expectedMessage: "Variable name must not be empty.");
     // OK
     refactoring.name = 'res';
     assertRefactoringStatusOK(refactoring.checkName());
   }
 
+  test_checkName_conflict_withInvokedFunction() async {
+    indexTestUnit('''
+main() {
+  int a = 1 + 2;
+  res();
+}
+
+void res() {}
+''');
+    _createRefactoringForString('1 + 2');
+    await refactoring.checkInitialConditions();
+    refactoring.name = 'res';
+    assertRefactoringStatus(
+        refactoring.checkName(), RefactoringProblemSeverity.ERROR,
+        expectedMessage: "The name 'res' is already used in the scope.");
+  }
+
+  test_checkName_conflict_withOtherLocal() async {
+    indexTestUnit('''
+main() {
+  var res;
+  int a = 1 + 2;
+}
+''');
+    _createRefactoringForString('1 + 2');
+    await refactoring.checkInitialConditions();
+    refactoring.name = 'res';
+    assertRefactoringStatus(
+        refactoring.checkName(), RefactoringProblemSeverity.ERROR,
+        expectedMessage: "The name 'res' is already used in the scope.");
+  }
+
+  test_checkName_conflict_withTypeName() async {
+    indexTestUnit('''
+main() {
+  int a = 1 + 2;
+  Res b = null;
+}
+
+class Res {}
+''');
+    _createRefactoringForString('1 + 2');
+    await refactoring.checkInitialConditions();
+    refactoring.name = 'Res';
+    assertRefactoringStatus(
+        refactoring.checkName(), RefactoringProblemSeverity.ERROR,
+        expectedMessage: "The name 'Res' is already used in the scope.");
+  }
+
   test_completeStatementExpression() {
     indexTestUnit('''
 main(p) {
   p.toString();
 }
 ''');
     _createRefactoringForString('p.toString()');
     // apply refactoring
     return _assertSuccessfulRefactoring('''
 main(p) {
@@ skipping 965 matching lines @@
   List<String> _getCoveringExpressions() {
     List<String> subExpressions = <String>[];
     for (int i = 0; i < refactoring.coveringExpressionOffsets.length; i++) {
       int offset = refactoring.coveringExpressionOffsets[i];
       int length = refactoring.coveringExpressionLengths[i];
       subExpressions.add(testCode.substring(offset, offset + length));
     }
     return subExpressions;
   }
 }