public void ReturnAnEmptyStringForInvalidColumn()
{
var sut = new ColumnHeaderHelper();
var headerString = sut.HeaderFor(-1);
Assert.Equal(string.Empty, headerString);
}
public void ReturnAValidHeaderString()
{
var sut = new ColumnHeaderHelper();
var headerString = sut.HeaderFor(1);
Assert.Equal("A", headerString);
}
public void ReturnAValidHeaderString_DoubleLength_End()
{
var sut = new ColumnHeaderHelper();
var headerString = sut.HeaderFor(52);
Assert.Equal("AZ", headerString);
}