CalculatorTests.cs

public class CalculatorTests
{
    [Theory]
    [MemberData(nameof(TestData))]
    public void CanAdd(int value1, int value2, int expected)
    {
        var calculator = new Calculator();
        var result = calculator.Add(value1, value2);
        Assert.Equal(expected, result);
    }

    public static IEnumerable<object[]> TestData =>
        new List<object[]>
        {
        new object[] { 1, 2, 3 },
        new object[] { -1, -2, -3 }
        };
}