Strings recipes for the Dart Cookbook

recipes/test/core/strings/removing_leading_trailing_whitespace_test.dart

Index: recipes/test/core/strings/removing_leading_trailing_whitespace_test.dart
diff --git a/recipes/test/core/strings/removing_leading_trailing_whitespace_test.dart b/recipes/test/core/strings/removing_leading_trailing_whitespace_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..659f50bfd1028e08c3c33756e7b8ded497bb0a64
--- /dev/null
+++ b/recipes/test/core/strings/removing_leading_trailing_whitespace_test.dart
@@ -0,0 +1,24 @@
+library removing_leading_trailing_whitespace_test;
+
+import "package:unittest/unittest.dart";
+
+void main() {
+  group('trimming whitespace from a string', () {
+    var space = '\n\r\f\t\v';
+    var string = '$space X $space';
+    
+    test('', () {
+      expect(string.trim(), equals('X'));
+    });
+
+    test('leading whitespace', () {
+      expect(string.replaceFirst(new RegExp(r'^\s+'), ''), equals('X $space'));
+    });
+
+    test('trailing whitespace', () {
+      expect(string.replaceFirst(new RegExp(r'\s+$'), ''), equals('$space X'));
+    });
+  });  
+  
+}
+