Firefox: Background event page gets terminated too early?

[powellnorma]

As others have described (e.g. #112 (comment) #93 (comment) #20 (comment), ..), the extension seems to not send the data reliably.

I suspect this might be due to the Background event page getting terminated too early:
https://github.com/Saghen/aw-watcher-web/blob/8ec8093b41e68a06c67f5e50218ec581901cf53a/src/background/heartbeat.ts#L67-L74

export const tabActivatedListener =
  (client: AWClient) =>
  async (activeInfo: browser.Tabs.OnActivatedActiveInfoType) => {
    const tab = await getTab(activeInfo.tabId)
    const tabs = await getTabs()
    console.debug('Sending heartbeat for tab activation', tab)
    heartbeat(client, tab, tabs.length)
  }

I suspect that before these awaits have finished, the background page is already terminated.

One hint for this is that when I debug the background page in Firefox:

1. This issue does not happen anymore (the timeline is continuous, before it had many empty spaced)
2. It says Background event page was not terminated on idle because a DevTools toolbox is attached to the extension. every now and then

https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Background_scripts

An easy fix might be to set persistent: true in the manifest.json: #107 (comment)

Ok just tried it, the latter seems to indeed fix the issue