public void CanPeekAheadNCharacters() { var empty = new Text(""); empty.Peek(0).ShouldBe(""); empty.Peek(1).ShouldBe(""); var abc = new Text("abc"); abc.Peek(0).ShouldBe(""); abc.Peek(1).ShouldBe("a"); abc.Peek(2).ShouldBe("ab"); abc.Peek(3).ShouldBe("abc"); abc.Peek(4).ShouldBe("abc"); abc.Peek(100).ShouldBe("abc"); }