How to mock a 501 error from ajax call

Question

I've got an http 501 error bubbling up in prod from this call:

return $.ajax({
    url: finalUrl,
    success: function (result) {
        console.log('success call result');
        console.log(result);
        finalResult = result;
    },
    data: JSON.stringify(data),
    type: 'PATCH',
    contentType: 'application/json'
});

How can I return a mock simulating the error so I can test a fix outside of production? I looked at the response tab in chrome and I see an HTML message:

<HTML><HEAD>
<TITLE>Unsupported Request</TITLE>
</HEAD><BODY>
<H1>Unsupported Request</H1>
PATCH to http&#58;&#47;&#47;demo&#46;site&#46;com&#47;serviceName&#47;v1&#47;requests&#47;9305e338&#45;666a&#45;e611&#45;8516&#45;000c291891bb not supported.<P>
Reference&#32;&#35;8&#46;f0fd717&#46;1472154919&#46;9959c96
</BODY></HTML>

We suspect that the API is not being hit at all, blocked by a firewall. I don't know if I should expect a string or object in this case? If object, then what are the members of that object?

Fiddler says:

Server: AkamaiGHost
Mime-Version: 1.0
Content-Type: text/html
Content-Length: 350
Expires: Thu, 25 Aug 2016 20:21:49 GMT
Date: Thu, 25 Aug 2016 20:21:49 GMT
Connection: close

My suggestion would be to use [Mockjax](https://github.com/jakerella/jquery-mockjax) - at allows you to capture any AJAX request and craft a custom response. — VLAZ, Aug 25 '16 at 20:19
Is there an HTTP code returned like, perhaps, 405 or 501? Otherwise you're left handling the raw HTML. **EDIT** too dumb to read today I guess. Sorry! — stdunbar, Aug 25 '16 at 20:25

score 0 · Answer 1 · edited May 23 '17 at 12:08

0

We suspect that the API is not being hit at all, blocked by a firewall.

From the error, it looks like you're hitting a back-end that isn't configured for that request-type.

See these questions for a potential solution, assuming you control the back-end too.

Does tomcat support http PATCH method?

How do I stop Apache httpd from rejecting HTTP PATCH requests?

If you do control the back-end, but the above doesn't help, make sure that your controller function supports that request method. In Spring, for example, you have to declare that explicitly:

@Controller
MyController {

   @Requestmapping(value = "/api/patchTheThing", method=RequestMethod.PATCH)
   @ResponseBody String patchTheThing(....) {
        ...
   }
}

edited May 23 '17 at 12:08

Community

1
1

answered Aug 25 '16 at 20:35

Jennifer Wood

80
1
4

We do control the backend. The issue only occurs in production. It does not happen in lower environments. That's why we think this is server/firewall related. – P.Brian.Mackey Aug 25 '16 at 20:57
Is the server architecture the same between dev and prod environments? E.g. do you connect directly to tomcat over port 8080 locally, but use apache + mod_proxy to connect over port 80/443 in production? If so, it's possible the answers linked above could help. – Jennifer Wood Aug 25 '16 at 21:01

Mike Brant · Answer 2 · 2016-08-25T20:43:03.893

0

Just set up an endpoint on a server of your choice and use your web server configure or coding language of your choice to issue a 501 response. But the problem seems pretty clear, the server is not expecting a PATCH request. If you had some networking problem you would not be getting a response at all.

you should strongly consider making sure your JavaScript code handles both happy path / success outcome as well as other types off sever response outcomes so your application can better handle how it wants to recover from such errors.

edited Aug 25 '16 at 20:43

answered Aug 25 '16 at 20:37

Mike Brant

70,514
10
99
103

We make PATCH requests to this API just fine. It's only under a very narrow circustance: In Prod and for people not on the VPN that this issue kicks up. – P.Brian.Mackey Aug 25 '16 at 20:58
Are people not on VPN not having having request proxied through or redirected to a different endpoint which does not support PATCH? – Mike Brant Aug 25 '16 at 21:00
They are proxied through yes. They use something called AkamaiGHost . I can't tell you what else is happening. The request should eventually make it down to our same API. That's all I know. – P.Brian.Mackey Aug 25 '16 at 21:06
Looks like you need to look at the request/response details to see where this response is coming from if not your app server. – Mike Brant Aug 25 '16 at 21:09

How to mock a 501 error from ajax call

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