spectre.console/test/Spectre.Console.Tests/Unit/Rendering/RenderHookTests.cs

namespace Spectre.Console.Tests.Unit;

public sealed class RenderHookTests
{
    private sealed class HelloRenderHook : IRenderHook
    {
        public IEnumerable<IRenderable> Process(RenderContext context, IEnumerable<IRenderable> renderables)
        {
            return new IRenderable[] { new Text("Hello\n") }.Concat(renderables);
        }
    }

    [Fact]
    public void Should_Inject_Renderable_Before_Writing_To_Console()
    {
        // Given
        var console = new TestConsole();
        console.Pipeline.Attach(new HelloRenderHook());

        // When
        console.Write(new Text("World"));

        // Then
        console.Lines[0].ShouldBe("Hello");
        console.Lines[1].ShouldBe("World");
    }
}