How can I implement error handling in ASP.NET middleware?

How can I implement error handling in ASP.NET middleware?

You can implement error handling in ASP.NET middleware by creating a custom middleware class that catches exceptions.

Can you show me a code example of that?

Sure! Here's a simple example:

public class ErrorHandlingMiddleware
{
    private readonly RequestDelegate _next;

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

    public async Task InvokeAsync(HttpContext context)
    {
        try
        {
            await _next(context);
        }
        catch (Exception ex)
        {
            // Log the exception
            // Return a custom error response
            context.Response.StatusCode = 500;
            await context.Response.WriteAsync("An error occurred: " + ex.Message);
        }
    }
}

Don't forget to register it in the Configure method of your Startup class!

What should I log when an error occurs?

You should log the exception message, stack trace, and any relevant context information, such as the request path and user details.

How can I test my error handling middleware?

You can test it by intentionally throwing exceptions in your application and verifying that your middleware handles them as expected.