IHttpContextAccessor and Exceptions handling

HttpContextAccessor.HttpContext.Session.cs

public class TestDataService
{
    private readonly IHttpContextAccessor _httpContextAccessor;

    // Inject IHttpContextAccessor into constructor
    public TestDataService(IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException(nameof(httpContextAccessor));
    }

    public string GetTestValue()
    {
        return _httpContextAccessor.HttpContext.Session.GetString("testKey");
    }
}

// https://ignas.me/tech/ihttpcontextaccessor-exceptions-handling/

IExceptionHandlerFeature.cs

[Route("[controller]")]
public class ErrorController : Controller
{
    private readonly IHttpContextAccessor _httpContextAccessor;
    private readonly ILogger _logger;

    public ErrorController(IHttpContextAccessor httpContextAccessor, ILoggerFactory loggerFactory)
    {
        _httpContextAccessor = httpContextAccessor;
        _logger = loggerFactory?.CreateLogger(nameof(ErrorController)) ?? throw new ArgumentNullException(nameof(loggerFactory));
    }

    [Route("")]
    public IActionResult Index()
    {
        // Get exception from the context using IExceptionHandlerFeature.
        var exception = _httpContextAccessor.HttpContext.Features.Get<IExceptionHandlerFeature>();
        if (exception != null)
        {
            _logger.LogError(1, exception.Error, "Unhandled exception occurred.");
        }

        return View("Index");
    }
}

// https://ignas.me/tech/ihttpcontextaccessor-exceptions-handling/

IHttpContextAccessorDependencyInjection.cs

public void ConfigureServices(IServiceCollection services)
{
        // Register IHttpContextAccessor with DI
        services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
        // Add Session
        services.AddSession();
        services.AddMvc();
}

UseExceptionHandler.cs

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    loggerFactory.AddConsole(_configuration.GetSection("Logging"));
    loggerFactory.AddDebug();
    // Send all unhandled exceptions to Error controller
    app.UseExceptionHandler("/Error");
    app.UseStaticFiles();
    app.UseMvc(routes => { routes.MapRoute("default", "{controller=Home}/{action=Index}/{id?}"); });
}