Getting Started

To use this library, simply include BunsenBurner.dll in your project or grab it from NuGet, and add this to the top of each test .cs file that needs it:

// for AAA style tests
using static BunsenBurner.ArrangeActAssert;

or

// for BDD style tests
using static BunsenBurner.GivenWhenThen;

Take an existing test,

[Fact(DisplayName = "SerializeAsync can work with anonymous objects")]
public async Task ExampleTest()
{
    // Arrange
    var widget = new { Name = "Widget1", Cost = 12.50 };
    var ms = new MemoryStream();

    // Act
    await JsonSerializer.SerializeAsync(
        ms,
        widget,
        cancellationToken: TestContext.Current.CancellationToken
    );

    // Assert
    Assert.Equal(
        expected: "{\"Name\":\"Widget1\",\"Cost\":12.5}",
        actual: Encoding.UTF8.GetString(ms.ToArray())
    );
}

This can be converted to use the test builder (DSL) like so,

[Fact(DisplayName = "SerializeAsync can work with anonymous objects")]
public Task ExampleTestUsingAaaBuilder() =>
    Arrange(() =>
        {
            var widget = new { Name = "Widget1", Cost = 12.50 };
            var ms = new MemoryStream();
            return (widget, ms);
        })
        .Act(async data =>
        {
            await JsonSerializer.SerializeAsync(data.ms, data.widget);
            return Encoding.UTF8.GetString(data.ms.ToArray());
        })
        .Assert(result =>
            Assert.Equal(expected: "{\"Name\":\"Widget1\",\"Cost\":12.5}", actual: result)
        );

Note

Tests must always return a Task to be compatible with the DSL.

This formalizes the structure and then opens up refactoring possibilities such as pulling out a shared act method,

[Fact(DisplayName = "SerializeAsync can work with anonymous objects")]
public Task ExampleTestUsingAaaBuilder2() =>
    Arrange(() =>
        {
            var widget = new { Name = "Widget1", Cost = 12.50 };
            var ms = new MemoryStream();
            return (widget, ms);
        })
        // pull out the shared test code
        .Act(CallSerializeAsync)
        .Assert(result =>
            Assert.Equal(expected: "{\"Name\":\"Widget1\",\"Cost\":12.5}", actual: result)
        );

// this is now a shared stage and can be used in many tests
private static async Task<string> CallSerializeAsync<T>((T, MemoryStream) data)
{
    var (widget, ms) = data;
    await JsonSerializer.SerializeAsync(ms, widget);
    return Encoding.UTF8.GetString(ms.ToArray());
}

The principle is simple, refine the test structure using a DSL then use the new structure to identify common code and DRY that code up.