Question

I have the following code:

protected IEnumerable<string> GetErrorsFromModelState() {

    var exceptions = ModelState.SelectMany(x => x.Value.Errors
        .Select(error => error.Exception.Message));

    var errors = ModelState.SelectMany(x => x.Value.Errors
        .Select(error => error.ErrorMessage));

    return exceptions.Union(errors);
}

Is there a way that I could stop this giving a nullReference Exception if:

error.Exception is null  or if error.Exception.Message is null

Both cases are giving me problems and I’m not sure how I can code this
with a IsNullOrEmpty check for both cases.

Answer 1

How about

protected IEnumerable<string> GetErrorsFromModelState()
{        
    var exceptions = ModelState.SelectMany(x => x.Value.Errors
                            .Where(error => (error != null) && 
                                            (error.Exception != null) &&
                                            (error.Exception.Message != null))
                            .Select(error => error.Exception.Message));

    var errors = ModelState.SelectMany(x => x.Value.Errors
                            .Where(error => (error != null) && 
                                            (error.ErrorMessage != null))
                            .Select(error => error.ErrorMessage));

    return exceptions.Union(errors);
}