public void CreateTable_WhenFactorsAreNull_ShouldThrowAnArgumentNullException()
{
// Arrange
var subject = new MultiplicationTableCalculator();
// Act
TestDelegate act = () => subject.CreateTable(null);
// Assert
var ex = Assert.Throws<ArgumentNullException>(act);
Assert.That(ex.ParamName, Is.EqualTo("factors"));
}
public void CreateTable_WhenFactorsAreNotNull_ReturnsATableWhoseTopRowIsTheListOfFactors()
{
// Arrange
var factors = Enumerable.Range(1, 5).ToArray();
var subject = new MultiplicationTableCalculator();
// Act
var result = subject.CreateTable(factors);
// Assert
for(int col = 1; col <= 5; col++)
{
Assert.That(result[0, col], Is.EqualTo(factors[col - 1]));
}
}
public void CreateTable_WhenFactorsAreNotNull_ReturnsATableWhoseFirstColumnIsTheListOfFactors()
{
// Arrange
var factors = Enumerable.Range(1, 5).ToArray();
var subject = new MultiplicationTableCalculator();
// Act
var result = subject.CreateTable(factors);
// Assert
for (int row = 1; row <= 5; row++)
{
Assert.That(result[row, 0], Is.EqualTo(factors[row - 1]));
}
}
public void CreateTable_WhenFactorsAreNotNull_ReturnsATableWhoseOtherValuesAreTheProductOfTheTopRowAndTheFirstColumn()
{
// Arrange
var factors = Enumerable.Range(1, 5).ToArray();
var subject = new MultiplicationTableCalculator();
// Act
var result = subject.CreateTable(factors);
// Assert
for (int col = 1; col <= 5; col++)
{
for (int row = 1; row <= 5; row++)
{
var expected = result[0, col] * result[row, 0];
Assert.That(result[row, col], Is.EqualTo(expected));
}
}
}
