Strings recipes for the Dart Cookbook

recipes/test/core/strings/getting_the_length_test.dart

Index: recipes/test/core/strings/getting_the_length_test.dart
diff --git a/recipes/test/core/strings/getting_the_length_test.dart b/recipes/test/core/strings/getting_the_length_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..ef9c3a5ffc75dc6a997509cdfc07ff080214ade0
--- /dev/null
+++ b/recipes/test/core/strings/getting_the_length_test.dart
@@ -0,0 +1,24 @@
+library getting_the_length_test;
+
+import 'package:unittest/unittest.dart';
+
+void main() {
+  group('getting the length of a string', () {
+    var clef = '\u{1F3BC}';
+    var hearts = '\u2661';
+    var music = 'I $hearts $clef';
+    
+    test('that contains only BMP symbols', () {
+      expect('I love music'.length, equals(12));
+      expect(hearts.length, equals(1));
+      expect(hearts.runes.length, equals(1));
+    });
+    
+    test('that contains non-BMP symbols', () {
+      expect(clef.length, equals(2));
+      expect(clef.runes.length, equals(1));
+      expect(music.length, equals(6));
+      expect(music.runes.length, equals(5));
+    });
+  });
+}