Memory leak in vue-i18next

[callumacrae]

Hey!

Have spent today tracking down a memory leak in our app, and figured out it's somewhere inside vue-i18next.

On projects with a lot of translations, it's a pretty significant leak. It also seems to keep the entire Vue instance alive.

After creating 1000 vue instances and throwing them away, this is what happens:

(look for everything with "1000" written in "New")

In theory, they should have been cleaned up by the garbage collector, but something is keeping them alive.

Here's a repository you can replicate the problem in: https://github.com/callumacrae/vue-i18next-leak

It's definitely vue-i18next, not i18next.

[callumacrae]

Oh, and to explain why this is an issue: on a standard project, this isn't an issue, but on projects with server-side rendering this causes the memory usage on the server to increase every time a request is made until the server crashes.

[callumacrae]

Alright, I've found the leak:

https://github.com/panter/vue-i18next/blob/master/src/i18n.js#L18-L23

Passing undefined to bindI18n and bindStore on the server seems to work around the issue.

Would be nice if there were a better way, though!