1236368 - Clicking link to browse page with friend does nothing (TypeError: result is undefined roomStore.js)

Status: RESOLVED FIXED

(Hello (Loop) :: Client, defect, P1)

Description

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

Can reproduce only sometimes:

Firefox Nightly 46.0a1 20160103 on Windows 8.1

Steps to reproduce:
1. Launch Nightly.
2. Menu File > New Non-e10s window.
3. Close e10s window.
4. Load https://bugzilla.mozilla.org in the remaining window.
5. Open a new tab and load https://wiki.mozilla.org
6. Click Hello button.
7. Click Intro link.
8. Go back to the Bugzilla tab.
9. Click Hello button.
10. Click button to browse page with friend.

Browser console shows:
TypeError: result is undefined roomStore.js:269:11

Comment 1

[Mark Banner (:standard8)]

Sebastian,

Can you try getting a log from the browser console which includes network operations when you click the button?

I'm especially interested in the time it takes for network connections to complete.

One thing I'm wondering here is if for some reason your connection to the server is taking > 5 seconds, or is dropping packets and you're not getting a response.

Comment 2

[Mark Banner (:standard8)]

Please see comment 1.

Comment 3

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

Wasn't able to reproduce this anymore in the last days.

Comment 4

[GitHub Autolander Bot]

Attachment: [loop] Standard8:bug-1236368-result > mozilla:master

Comment 5

[Mark Banner (:standard8)]

Comment on attachment 8705598 [details] [review]
[loop] Standard8:bug-1236368-result > mozilla:master

Although Sebastian can't reproduce this any more, I took another look at the code.

All I can really see is that if the request takes longer than 5 seconds for some reason, then the loop api code will time out, and we won't get an error back (due to the way its designed) - result is undefined, hence the error.

I can't think of why a request would take longer than 5 seconds, unless there's network/server issues, but in any case, we should report it back to the user.

Hence this patch handles the result being undefined. Mike, can you think of anything else we should consider here?

Comment 6

[Mike de Boer [:mikedeboer]]

(In reply to Mark Banner (:standard8) from comment #5)
> All I can really see is that if the request takes longer than 5 seconds for
> some reason, then the loop api code will time out, and we won't get an error
> back (due to the way its designed) - result is undefined, hence the error.

Thinking about this a bit led me to believe that we should return the result with an error in the timeout case. I think resolving with 'undefined' in the timeout case is not resulting in clean code-flows. In MozLoopAPI we now always reply() in each handler, so timeouts shouldn't occur anymore.

I can't think of another way that the result would be 'undefined'.

Comment 7

[Mike de Boer [:mikedeboer]]

Comment on attachment 8705598 [details] [review]
[loop] Standard8:bug-1236368-result > mozilla:master

Ah forgot to r+ this one after I wrote comment 6. Would you like to file a follow-up to implement what I suggested there? I'd be willing to work on it.

Comment 8

[Mark Banner (:standard8)]

https://github.com/mozilla/loop/commit/557dd8844e5fa21d1e6e5da909df073849fc55ed