Telemetry not cached during network disconnects

[ctenden]

Tracking of telemetry appears to be lost if TRACK POST is performed while network is down.

Reproduction Steps:
With Network On
Perform a trackEvent
Wait for TRACK POST
Perform a trackEvent
Turn off Network
Wait for TRACK POST
Turn on network
Perform a trackEvent
Wait for TRACK POST

In Insights, only trackEvent 1 and 3 are captured.

Is it possible to use navigator.online to decide whether or not to perform TRACK POST?

[MarkPieszak]

Would it be easier to do this on the app-side?
Are you talking about storing things in an Collection if it's offline and sending the event when it comes back on?

[ctenden]

Correct. Telemetry collected before a disconnect and during a disconnect IF the attempt is made to TRACK, is lost. Telemetry collected during a disconnect but reconnects before the TRACK is fine.

[GustavoAmerico]

@ctenden
This behavior is caused in the original implementation, I found the file responsible for the http request, but I will not be able to implement and test it in the next days. Try opening an Issue in the repository:
https://github.com/Microsoft/ApplicationInsights-JS/blob/master/JavaScript/JavaScriptSDK/Sender.ts