Issue 22644. Fix for removing non-Dartdoc comments before a declaration.

pkg/analyzer/test/generated/incremental_resolver_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 engine.incremental_resolver_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
@@ skipping 2825 matching lines @@
 }
 ''');
     _updateAndValidate(r'''
 main() {
   // edited comment text
   print(0);
 }
 ''');
   }
 
+  void test_endOfLineComment_header_add() {
+    _resolveUnit(r'''
+main() {
+  Object x;
+  x.foo();
+}
+''');
+    _updateAndValidate(r'''
+// 000
+main() {
+  Object x;
+  x.foo();
+}
+''');
+  }
+
+  void test_endOfLineComment_header_remove() {
+    _resolveUnit(r'''
+// 000
+main() {
+  Object x;
+  x.foo();
+}
+''');
+    _updateAndValidate(r'''
+main() {
+  Object x;
+  x.foo();
+}
+''');
+  }
+
+  void test_endOfLineComment_header_update() {
+    _resolveUnit(r'''
+// 000
+main() {
+  Object x;
+  x.foo();
+}
+''');
+    _updateAndValidate(r'''
+// 10
+main() {
+  Object x;
+  x.foo();
+}
+''');
+  }
+
   void test_endOfLineComment_localFunction_inTopLevelVariable() {
     _resolveUnit(r'''
 typedef int Binary(one, two, three);
 
 int Global = f((a, b, c) {
   return 0; // Some comment
 });
 ''');
     _updateAndValidate(r'''
 typedef int Binary(one, two, three);
@@ skipping 901 matching lines @@
     return ResolutionContextBuilder.contextFor(node, listener).scope;
   }
 }
 
 class _Edit {
   final int offset;
   final int length;
   final String replacement;
   _Edit(this.offset, this.length, this.replacement);
 }