Strings recipes for the Dart Cookbook

recipes/test/core/strings/changing_string_case_test.dart

+library changing_string_case_test;
+
+import 'package:unittest/unittest.dart';
+
+void main() {
+group('changing string case', () {
+    var theOneILove = 'I love Lucy!';
+
+    test('with toUpperCase()', () {
+      expect(theOneILove.toUpperCase(), equals('I LOVE LUCY!'));
+    });
+    
+    test('with toLowerCase()', () {
+      expect(theOneILove.toLowerCase(), equals('i love lucy!'));
+    });
+    
+    test('with bicameral characters', () {
+      var zeus = '\u0394\u03af\u03b1\u03c2'; // Δίας
+      var resume = '\u0052\u00e9\u0073\u0075\u006d\u00e9'; // Résumé
+      expect(zeus.toLowerCase(), equals('δίας'));
+      expect(zeus.toUpperCase(), equals('ΔΊΑΣ'));
+      expect(resume.toLowerCase(), equals('résumé'));
+      expect(resume.toUpperCase(), equals('RÉSUMÉ'));
+    });
+
+    test('with unicameral characters', () {
+      var chickenKebab = '\u091a\u093f\u0915\u0928 \u0915\u092c\u093e\u092c'; 
+      // चिकन कबाब
+      expect(chickenKebab.toLowerCase(), equals(chickenKebab));
+      expect(chickenKebab.toUpperCase(), equals(chickenKebab));
+    });
+  });
+}
+