public void WhenPreviousIsNull_ReturnsFirstItem()
{
//Arrange
var expected = "Joe";
var list = new[] { expected, "Michael", "Jane" };
//Act
var result = list.NextElement(null);
//Assert
Assert.AreEqual(expected, result);
}
public void WhenPreviousIsLastItem_ReturnsFirstItem()
{
//Arrange
var previous = "Bob";
var expected = "Joe";
var list = new[] { expected, "Michael", previous };
//Act
var result = list.NextElement(previous);
//Assert
Assert.AreEqual(expected, result);
}
public void WhenEnumerableHasItems_ReturnsNextItem()
{
//Arrange
var previous = "Bob";
var expected = "Joe";
var list = new[] { "Michael", previous, expected };
//Act
var result = list.NextElement(previous);
//Assert
Assert.AreEqual(expected, result);
}