feat(logger): add link

packages/mason_logger/example/main.dart

@@ -46,5 +46,10 @@ Future<void> main() async {
   final canceling = logger.progress('Trying to cancel now!');
   await Future<void>.delayed(const Duration(seconds: 1));
   canceling.cancel();
-  logger.info('Done!');
+
+  final repoLink = link(
+    message: 'GitHub Repository',
+    uri: Uri.parse('https://github.com/felangel/mason'),
+  );
+  logger.info('To learn more, visit the $repoLink.');
 }

packages/mason_logger/lib/mason_logger.dart

@@ -2,4 +2,5 @@ library mason_logger;
 
 export 'src/io.dart';
 export 'src/level.dart';
+export 'src/link.dart';
 export 'src/mason_logger.dart' show Logger, Progress;

packages/mason_logger/lib/src/link.dart

@@ -0,0 +1,17 @@
+/// Wraps [uri] with an escape sequence so it's recognized as a hyperlink.
+/// An optional message can be used in place of the [uri].
+/// If no [message] is provided, the text content will be the full [uri].
+///
+/// ```dart
+/// final plainLink = link(uri: Uri.parse('https://dart.dev'));
+/// print(plainLink); // Equivalent to `[https://dart.dev](https://dart.dev)` in markdown
+///
+/// final richLink = link(uri: Uri.parse('https://dart.dev'), message: 'The Dart Website');
+/// print(richLink); // Equivalent to `[The Dart Website](https://dart.dev)` in markdown
+/// ```
+String link({required Uri uri, String? message}) {
+  const leading = '\x1B]8;;';
+  const trailing = '\x1B\\';
+
+  return '$leading$uri$trailing${message ?? uri}$leading$trailing';
+}

packages/mason_logger/test/src/link_test.dart

@@ -0,0 +1,32 @@
+import 'package:mason_logger/mason_logger.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('link', () {
+    final uri = Uri.parse('https://github.com/felangel/mason/issues/');
+    const lead = '\x1B]8;;';
+    const trail = '\x1B\\';
+
+    test(
+      'builds output with correct encodings: ' r'\x1B]8;;' ' and ' r'\x1B\\',
+      () {
+        const message = 'message';
+        final output = link(message: message, uri: uri);
+        final matcher = stringContainsInOrder(
+          [lead, '$uri', trail, message, lead, trail],
+        );
+
+        expect(output, matcher);
+      },
+    );
+
+    test('builds String with Uri when message is null: ', () {
+      final output = link(uri: uri);
+      final matcher = stringContainsInOrder(
+        [lead, '$uri', trail, '$uri', lead, trail],
+      );
+
+      expect(output, matcher);
+    });
+  });
+}