Simple assert class to be used with ASP.NET MVC projects.

I wanted a way to call asserts inside ASP.NET MVC code. Using the usual Debug.Assert ins't ideal - yes you can configure your ASP.NET MVC website to show the failed assert dialog, but it's not a great developer experience.

I've created a custom assert class named WebAssert. Here is an example of how to use it...

public ActionResult Index(string imagePath = "")
{
    WebAssert.Assert(() => !string.IsNullOrEmpty(imagePath), "The param 'imagePath' must not be empty.");

    return View();
}

When an assert fails, one of two things will happen, depending on whether you are attached to the website with a debugger.

The code will break inside WebAssert.Assert() giving you the chance to navigate the call stack in order to investigate why the assertion has failed. Also, some debug information will be outputted to the 'Immediate Window' to give you a head start on what has happened...

If no debugger is attached, then the failed assertion details will be outputted to the browser, using a HTML file as a template.

The HTML file is called AssertFailed.cshtml. Here is an example of what you will see when an assertion fails...