BestPractices.md

Best Practices

• Consider naming fixtures, methods and functions from a users' point-of-view
• Stick to Arrange-Act-Assert conventions
• Test fixtures should be Snake_cased
• Test methods should be snake_cased
• Test functions should be snake_cased
• Divide test functions with new line
• Test functions should be a single line statement
• Do not use curly brackets for single line test functions
• Fields should appear first in a test fixture
• Do not use visibility modifiers on fields

Consider naming fixtures, methods and functions from a users' point-of-view

✔️ Consider:

public class Given_a_car
{
    Car subject;
    bool is_stopped;

    [SetUp]
    public void SetUp() =>
        subject = new Car();

    [LoFu, Test]
    public void when_stopped()
    {
        is_stopped = subject.Stop();

        void should_turn_off_the_engine() =>
            is_stopped.Should().BeTrue();
    }
}

❌ Avoid:

public class CarTests
{
    Car car;
    bool value;

    [SetUp]
    public void SetUp() =>
        car = new Car();

    [LoFu, Test]
    public void Stop()
    {
        value = car.Stop();

        // What should be true? The test output will be ambiguous!
        void should_be_true() =>
            value.Should().BeTrue();
    }
}

Stick to Arrange-Act-Assert conventions

Test fixture SetUp is for arrange, test method is for acting, and test functions should be used for asserting.

public class Given_a_car
{
    Car subject;
    bool is_stopped;

    [SetUp]
    public void SetUp() =>
        subject = new Car(); // arrange

    [LoFu, Test]
    public void when_stopped()
    {
        is_stopped = subject.Stop(); // act

        void should_turn_off_the_engine() =>
            is_stopped.Should().BeTrue(); // assert
    }
}

Test fixtures should be Snake_cased

The test fixtures should begin with Given and be Snake_cased

✔️ Consider:

public class Given_a_car
{
}

❌ Avoid:

public class GivenACar
{
}

Test methods should be snake_cased

The test methods should begin with when and be snake_cased

✔️ Consider:

[LoFu, Test]
public void when_stopped()
{
}

❌ Avoid:

[LoFu, Test]
public void WhenStopped()
{
}

Test functions should be snake_cased

The test functions should begin with should and be snake_cased

✔️ Consider:

void should_turn_off_engine() =>
    is_stopped.Should().BeTrue();

❌ Avoid:

void ShouldTurnOffEngine() =>
    is_stopped.Should().BeTrue();

Divide test functions with new line

✔️ Consider:

void should_turn_off_the_engine() =>
    is_stopped.Should().BeTrue();

❌ Avoid:

void should_turn_off_the_engine() => is_stopped.Should().BeTrue();

Test functions should be a single line statement

✔️ Consider:

void should_turn_off_engine() =>
    is_stopped.Should().BeTrue();

❌ Avoid:

void should_turn_off_engine()
{
    var stopped = subject.Stop();

    stopped.Should().BeTrue();
}

Do not use curly brackets for single line test functions

✔️ Consider:

void should_turn_off_the_engine() =>
    is_stopped.Should().BeTrue();

❌ Avoid:

void should_turn_off_the_engine() =>
{
    is_stopped.Should().BeTrue();
}

Fields should appear first in a test fixture

✔️ Consider:

public class Given_a_car
{
    bool is_stopped;

    [LoFu, Test]
    public void when_stopped()
    {
        is_stopped = subject.Stop();

        void should_turn_off_the_engine() =>
            is_stopped.Should().BeTrue();
    }
}

❌ Avoid:

public class Given_a_car
{
    [LoFu, Test]
    public void when_stopped()
    {
        is_stopped = subject.Stop();

        void should_turn_off_the_engine() =>
            is_stopped.Should().BeTrue();
    }

    bool is_stopped;
}

Do not use visibility modifiers on fields

✔️ Consider:

public class Given_a_car
{
    bool is_stopped;
}

❌ Avoid:

public class Given_a_car
{
    private bool is_stopped;
}