public void Deletions()
{
//0123456789012345678901234
var sut = new LineEditor("ab cd efg hijklmn op qrst", 5);
var index = sut.Delete(12);
Assert.AreEqual(12, index);
//012345678901234567890123
Assert.AreEqual("ab cd efg hiklmn op qrst", sut.Line);
Assert.AreEqual(new[] { "ab cd ", "efg ", "hiklm", "n op ", "qrst" }, sut.SoftLines);
index = sut.Delete(23);
Assert.AreEqual(22, index);
//012345678901234567890123
Assert.AreEqual("ab cd efg hiklmn op qrs", sut.Line);
Assert.AreEqual(new[] { "ab cd ", "efg ", "hiklm", "n op ", "qrs" }, sut.SoftLines);
index = sut.Delete(5);
Assert.AreEqual(5, index);
Assert.AreEqual("ab cdefg hiklmn op qrs", sut.Line);
Assert.AreEqual(new[] { "ab ", "cdefg ", "hiklm", "n op ", "qrs" }, sut.SoftLines);
}