Response contains HTTP code 200 and error in body if client sends an email when disconnected from Internet

[ilya-chumakov]

Issue Summary

When I try to send an email without network connection to remote SMTP server, a response contains 200 OK in StatusCode and HttpRequestException in Body. I think it denies basic HTTP principles and such behaviour is completely unclear. I propose to throw a real exception. If impossible, the code from 4xx-5xx range should be used.

Steps to Reproduce

var sg = new SendGridAPIClient("my_api_key");

Mail mail = new Mail(from, subject, to, content);

//disconnect from Internet before executing this line
var response = await sg.client.mail.send.post(requestBody: mail.Get());

//writes "OK"
Console.WriteLine(response.StatusCode);

//writes ".NET HttpRequestException, raw message: An error occurred while sending the request"
Console.WriteLine(response.Body.ReadAsStringAsync().Result);

Technical details:

• sendgrid-csharp Version: v8.0.5
• .NET Version: 4.5.2

[thinkingserious]

Hi @chumakov-ilya,

Thanks! We agree and I've added this to our backlog for a fix.

[ottomatic]

I could look into submitting a pull request for this if the library maintainers are interested.

[thinkingserious]

Hello @ottomatic,

A PR is always welcome :)

We would just need a signed CLA to accept it.

Thanks!

With Best Regards,

Elmer

[JonCognioDigital]

We've been having huge problems with this too. It's completely misleading. It shouldn't even be an HTTP response because it didn't even get that far. It's just a piece of c# code calling another piece of .net code and should get an appropriate exception. If it does have to be an HTTP response then @chumakov-ilya is correct it should be an error code.

[thinkingserious]

@jon64digital,

Thanks for the feedback, we have added your vote to the issue.

@ottomatic,

Are you still considering a PR? A few days ago we made the CLA process much easier. You no longer need to sign the CLA I linked to previously. When you make your PR, a link will be generated and all you need to do is click the link, fill out a few fields and then sign it by clicking a button.

[ottomatic]

@thinkingserious ,

Yes, still intending to do this.
I have been busy consuming the SMTP Api instead, since our production servers don't allow outgoing http(s) through the firewall - whereas SMTP on port 587 is allowed.

One thing I would like to do in order to make unit testing easier is to take an HttpClient as an injected dependency in the SendGridAPIClient constructor. This would make it possible to inject a custom RequestHandler into the HttpClient, and in that way take control over the http response. What do you think of this change?

[SendGridDX]

Hello @ottomatic,

I suggest you add a third constructor that allows for injecting the custom RequestHandler into the HttpClient.

Thanks!

Elmer

[Jericho]

@ottomatic If you want a "web-proxy-friendly" C# client for the SendGrid API with injectable HttpClient please have a look at StrongGrid (on github and on nuget).

Also, while we are on the topic of mocking HttpClient calls, whether you decide to use StrongGrid or not I highly recommend you have a look at Richard Szalay's Mockhttp for HttpClient (on github and on nuget) which makes mocking HttpClient very easy. I have used it in a few unit testing projects to mock http calls and couldn't be more impressed.

[SendGridDX]

My apologies @ottomatic,

I was thinking of another SDK. We do have support for Web Proxies in this library: https://github.com/sendgrid/sendgrid-csharp/blob/master/src/SendGrid/SendGridClient.cs#L45

@Jericho,

Thanks for the suggestions on mocking HttpClient calls, very cool!

[Jericho]

@SendGridDX the constructor you pointed out does allow injecting IWebProxy but not HttpClient. Therefore it doesn't allow mocking htpp calls which is what @ottomatic wants to achieve.

I did a little research and found a PR submitted in June 2015 to allow httpclient to be injected but unfortunately it wasn't accepted.

[SendGridDX]

Thanks @Jericho!

@ottomatic,

Does this point you in the right direction? If you have any further questions, please don't hesitate to reach out.