Issue 23068. Constructors should have the same const/factory modifiers to match.

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 287 matching lines @@
 class M<T> {}
 class A {}
 class B<T extends A> = Object with M<T>;
 ''', r'''
 class M<T> {}
 class A {}
 class B<T> = Object with M<T>;
 ''');
   }
 
+  void test_false_constructor_keywordConst_add() {
+    _assertDoesNotMatch(r'''
+class A {
+  A();
+}
+''', r'''
+class A {
+  const A();
+}
+''');
+  }
+
+  void test_false_constructor_keywordConst_remove() {
+    _assertDoesNotMatch(r'''
+class A {
+  const A();
+}
+''', r'''
+class A {
+  A();
+}
+''');
+  }
+
+  void test_false_constructor_keywordFactory_add() {
+    _assertDoesNotMatch(r'''
+class A {
+  A();
+  A.foo() {
+    return new A();
+  }
+}
+''', r'''
+class A {
+  A();
+  factory A.foo() {
+    return new A();
+  }
+}
+''');
+  }
+
+  void test_false_constructor_keywordFactory_remove() {
+    _assertDoesNotMatch(r'''
+class A {
+  A();
+  factory A.foo() {
+    return new A();
+  }
+}
+''', r'''
+class A {
+  A();
+  A.foo() {
+    return new A();
+  }
+}
+''');
+  }
+
   void test_false_constructor_parameters_list_add() {
     _assertDoesNotMatch(r'''
 class A {
   A();
 }
 ''', r'''
 class A {
   A(int p);
 }
 ''');
@@ skipping 3698 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);
 }