What types of tests have you created in your projects?

In my projects, I have created the following types of tests in C#:

• Unit Tests for checking individual methods and classes using NUnit or MSTest.
• Integration Tests to verify the interaction between components.
• Functional Tests that check the business logic of the application.

Example of a simple unit test with NUnit:

using NUnit.Framework;

public class CalculatorTests
{
    [Test]
    public void Add_TwoNumbers_ReturnsSum()
    {
        var calculator = new Calculator();
        int result = calculator.Add(2, 3);
        Assert.AreEqual(5, result);
    }
}

public class Calculator
{
    public int Add(int a, int b) => a + b;
}