Add test for dot shorthands (#4089)

Author: szakarias

test/dot_shorthands_test.dart

@@ -0,0 +1,79 @@
+// Copyright (c) 2025, 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.
+import 'package:test/test.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import 'dartdoc_test_base.dart';
+import 'src/utils.dart';
+
+void main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(DotShorthandsTest);
+  });
+}
+
+@reflectiveTest
+class DotShorthandsTest extends DartdocTestBase {
+  @override
+  String get libraryName => 'dot_shorthands';
+
+  void test_doc_dot_shorthand_property_access_success() async {
+    var library = await bootPackageWithLibrary('''
+enum Color {
+  red, green
+}
+
+class C {
+  /// [Color] can be referenced but [.red] cannot.
+  void m(Color p) {}
+
+}
+''');
+    var m = library.classes.named('C').instanceMethods.named('m');
+
+    expect(m.hasDocumentationComment, true);
+    expect(
+      m.documentationAsHtml,
+      '<p><a href="$linkPrefix/Color.html">Color</a> can be referenced but '
+      '<code>.red</code> cannot.</p>',
+    );
+  }
+
+  void test_doc_dot_shorthand_constructor_invocation_success() async {
+    var library = await bootPackageWithLibrary('''
+class C {
+  /// Cannot link [.c()]
+  void m(String p) {}
+
+  C.c();
+}
+''');
+    var m = library.classes.named('C').instanceMethods.named('m');
+
+    expect(m.hasDocumentationComment, true);
+    expect(
+      m.documentationAsHtml,
+      '<p>Cannot link <code>.c()</code></p>',
+    );
+  }
+
+  void test_doc_dot_shorthand_method_invocation_success() async {
+    var library = await bootPackageWithLibrary('''
+class C {
+  /// Cannot link [.f()]
+  void m(String p) {}
+
+
+  static C f() => C();
+}
+''');
+    var m = library.classes.named('C').instanceMethods.named('m');
+
+    expect(m.hasDocumentationComment, true);
+    expect(
+      m.documentationAsHtml,
+      '<p>Cannot link <code>.f()</code></p>',
+    );
+  }
+}