Dual Google Analytics Pings on Initial Page Load

[derek-knox]

• I confirm that this is an issue rather than a question.

Bug report

Steps to reproduce

VuePress instances including https://vuepress.vuejs.org/ are receiving duplicate Google Analytics tracking pings on initial page load

What is expected?

Only one "collect" ping on initial page load

What is actually happening?

Two "collect" pings are occurring on initial page load

Other relevant information

Repro:

1. Go to https://vuepress.vuejs.org/
2. Ensure Network tab is displayed with filtering of google-analytics
3. Refresh the page
4. Note two, not one, tracking ping

[meteorlxy]

Not only google-analytics, but also other plugins that send request on initial page load.

[ajitzero]

I cannot reproduce this. Tried with Firefox and Chrome, but I'm only getting the expected single ping.

[meteorlxy]

@ajitzero You can try to repro this with serviceWorker enabled

[ajitzero]

Alright, I managed to reproduce this on both browsers.

Next, I found the relevant code for this in enhanceAppFile.js. I'd like to take up this issue (as a first-timer here!) and any suggestions are welcome!

So here is what I think is happening. The first ping is sent during the first initialization of the vuepress blog/instance (for any route) without the dp param from Google Analytics. This ping happens only once, on Line 21. And then, for every change in route, Line 23 calls router.afterEach() to send the next ping, which now includes the dp param. Now, one possible reason is that vue-router is considering the first/original route for .afterEach() as well (The docs are not clear about that). I suggest simply deleting Line 21, since the .afterEach() gets triggered anyway and sends the expected (single) ping.

Edit: Reference

[kefranabg]

Thanks @ajitzero