Strings recipes for the Dart Cookbook

recipes/test/core/strings/processing_a_string_one_character_test.dart

Index: recipes/test/core/strings/processing_a_string_one_character_test.dart
diff --git a/recipes/test/core/strings/processing_a_string_one_character_test.dart b/recipes/test/core/strings/processing_a_string_one_character_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..69f89aa4ab35cc9bae6e9191385b6a05f5f5bd61
--- /dev/null
+++ b/recipes/test/core/strings/processing_a_string_one_character_test.dart
@@ -0,0 +1,30 @@
+library processing_a_string_one_character_test;
+
+import 'package:unittest/unittest.dart';
+
+void main() {
+  
+
+  group('processing a string one character at a time', () {
+    var smileyFace = '\u263A';
+    var happy = 'I am $smileyFace';
+    var clef = '\u{1F3BC}';
+    
+    test('on rune boundary', () {
+      expect("Dart".runes.map((rune) => '*${new String.fromCharCode(rune)}*').toList(),
+          equals(['*D*', '*a*', '*r*', '*t*']));
+      
+      expect(happy.runes.map((rune) => [rune, new String.fromCharCode(rune)]).toList(), 
+          equals([ [73, 'I'], [32, ' '], [97, 'a'], [109, 'm'], [32, ' '], [9786, '☺'] ]));
+      
+      expect(clef.runes.map((rune) => new String.fromCharCode(rune)).toList(), 
+          equals(['\u{1F3BC}']));
+    });
+
+    test('on code-unit boundary', () {
+      expect('Dart'.split(''), equals(['D', 'a', 'r', 't']));
+      expect(smileyFace.split('').length, equals(1));
+      expect(clef.split('').length, equals(2));
+    });
+  });
+}