Warn about conflict before renamed class member and enclosing class name.

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

Index: pkg/analysis_server/test/services/refactoring/rename_class_member_test.dart
diff --git a/pkg/analysis_server/test/services/refactoring/rename_class_member_test.dart b/pkg/analysis_server/test/services/refactoring/rename_class_member_test.dart
index ef91205f45c594f4d46750108105f9e4446e40f7..43a0a351b947f763636e4034b07c2598a3f4a198 100644
--- a/pkg/analysis_server/test/services/refactoring/rename_class_member_test.dart
+++ b/pkg/analysis_server/test/services/refactoring/rename_class_member_test.dart
@@ -19,6 +19,60 @@ main() {
 
 @reflectiveTest
 class RenameClassMemberTest extends RenameRefactoringTest {
+  test_checkFinalConditions_classNameConflict_sameClass() async {
+    indexTestUnit('''
+class NewName {
+  void test() {}
+}
+''');
+    createRenameRefactoringAtString('test() {}');
+    // check status
+    refactoring.newName = 'NewName';
+    RefactoringStatus status = await refactoring.checkFinalConditions();
+    assertRefactoringStatus(status, RefactoringProblemSeverity.ERROR,
+        expectedMessage:
+            "Renamed method has the same name as the declaring class 'NewName'.",
+        expectedContextSearch: 'test() {}');
+  }
+
+  test_checkFinalConditions_classNameConflict_subClass() async {
+    indexTestUnit('''
+class A {
+  void test() {} // 1
+}
+class NewName extends A {
+  void test() {} // 2
+}
+''');
+    createRenameRefactoringAtString('test() {} // 1');
+    // check status
+    refactoring.newName = 'NewName';
+    RefactoringStatus status = await refactoring.checkFinalConditions();
+    assertRefactoringStatus(status, RefactoringProblemSeverity.ERROR,
+        expectedMessage:
+            "Renamed method has the same name as the declaring class 'NewName'.",
+        expectedContextSearch: 'test() {} // 2');
+  }
+
+  test_checkFinalConditions_classNameConflict_superClass() async {
+    indexTestUnit('''
+class NewName {
+  void test() {} // 1
+}
+class B extends NewName {
+  void test() {} // 2
+}
+''');
+    createRenameRefactoringAtString('test() {} // 2');
+    // check status
+    refactoring.newName = 'NewName';
+    RefactoringStatus status = await refactoring.checkFinalConditions();
+    assertRefactoringStatus(status, RefactoringProblemSeverity.ERROR,
+        expectedMessage:
+            "Renamed method has the same name as the declaring class 'NewName'.",
+        expectedContextSearch: 'test() {} // 1');
+  }
+
   test_checkFinalConditions_hasMember_MethodElement() async {
     indexTestUnit('''
 class A {