008 - StopwatchMiddleWare.cs

public class StopwatchMiddleWare
{
    private readonly RequestDelegate _next;

    public StopwatchMiddleWare(RequestDelegate next)
    {
        _next = next;
    }

    public async  Task Invoke(HttpContext context)
    {
        var s = new Stopwatch();
        s.Start();
        
        await _next(context);
        
        s.Stop();
        var result = s.ElapsedMilliseconds;        
        await context.Response.WriteAsync($" Time needed: {result }");
    }
}



public static class StopwatchMiddlewareExtension
{
    public static IApplicationBuilder UseStopwatch(this IApplicationBuilder app)
    {
        app.UseMiddleware<StopwatchMiddleware>();
        return app;
    }
}