Issue 25538. Fix for notification and private methods.

pkg/analysis_server/test/analysis/notification_overrides_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.analysis.notification.overrides;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/constants.dart';
@@ skipping 211 matching lines @@
   fff(x) {} // A
 }
 class B extends A {
   set fff(x) {} // B
 }
 ''');
     await prepareOverrides();
     assertNoOverride('fff(x) {} // B');
   }
 
+  test_BAD_privateByPrivate_inDifferentLib() async {
+    addFile(
+        '$testFolder/lib.dart',
+        r'''
+class A {
+  void _m() {}
+}
+''');
+    addTestFile('''
+import 'lib.dart';
+class B extends A {
+  void _m() {} // in B
+}
+''');
+    await prepareOverrides();
+    assertNoOverride('_m() {} // in B');
+  }
+
   test_BAD_setterByGetter() async {
     addTestFile('''
 class A {
   set fff(x) {}
 }
 class B extends A {
   get fff => null;
 }
 ''');
     await prepareOverrides();
@@ skipping 265 matching lines @@
 class C extends B {
   m() {} // in C
 }
 ''');
     await prepareOverrides();
     assertHasOverride('m() {} // in C');
     assertHasSuperElement('m() {} // in A');
     assertNoInterfaceMembers();
   }
 
+  test_super_method_privateByPrivate() async {
+    addTestFile('''
+class A {
+  _m() {} // in A
+}
+class B extends A {
+  _m() {} // in B
+}
+''');
+    await prepareOverrides();
+    assertHasOverride('_m() {} // in B');
+    assertHasSuperElement('_m() {} // in A');
+    assertNoInterfaceMembers();
+  }
+
   test_super_method_superTypeCycle() async {
     addTestFile('''
 class A extends B {
   m() {} // in A
 }
 class B extends A {
   m() {} // in B
 }
 ''');
     await prepareOverrides();
     // must finish
   }
 
   test_super_setterBySetter() async {
     addTestFile('''
 class A {
   set fff(x) {} // in A
 }
 class B extends A {
   set fff(x) {} // in B
 }
 ''');
     await prepareOverrides();
     assertHasOverride('fff(x) {} // in B');
     assertHasSuperElement('fff(x) {} // in A');
     assertNoInterfaceMembers();
   }
 }