import 'package:combinator/combinator.dart'; import 'package:test/test.dart'; import 'common.dart'; main() { var parser = match('hello').value((r) => 'world'); test('sets value', () { expect(parser.parse(scan('hello world'))!.value, 'world'); }); test('no value if no match', () { expect(parser.parse(scan('goodbye world'))!.value, isNull); }); }