fix TypeError: Cannot redefine property: $i18n

[HadiChen]

fix #421

[jgribonvald]

I confirm this change solves the TypeError !

[jgribonvald]

Why this was closed ?
even in version 8.1.0 it solves the TypeError !

[HadiChen]

I have already solved this problem on the project, and this error will occur in the special use of the project.
I have reopened this pr @jgribonvald

[jgribonvald]

@HadiChen could you point the commit that should solve the problem ?

After this commit solve the problem in web-component context where you can deploy and try to attach several instance of the vue-i18n component. So it could be usefull to avoid a TypeError for this use case.

Thanks

[cjosh]

Just chiming in that I was also waiting for a fix for this. I have a library of Vue components that's using Vue-i18n which is being used in another, larger Vue app that's also using Vue-i18n.

[HadiChen]

as long as the vue-i18n used in the project is the same, this error will not occur.

[cjosh]

I still get the error, with both of my package.jsons using the newest 8.1.0.

Edit: If I remove Vue-i18n from the library components, it seems to work and it will use the main project's Vue-i18n. So I just can't have two copies. I think I misunderstood what you were saying.

Edit 2: And while it does work, my console is now spammed (unsuprisingly with TypeError: "_vm.$t is not a function")

[HadiChen]

Can you explain the error in detail?

[cjosh]

So, like previously mentioned I get TypeError: can't redefine non-configurable property "$i18n" when both my main app and my component library (exported as vue components and used as a node module per https://medium.com/justfrontendthings/how-to-create-and-publish-your-own-vuejs-component-library-on-npm-using-vue-cli-28e60943eed3) is using Vue-i18n.

If I use Vue-i18n only on the library, I can load the app, but I can't use Vue-i18n on it.

If I remove Vue-i18n from the library, and only include it in the main app. It will load, but I get a bunch of console errors:
[Vue warn]: Error in render: "TypeError: _vm.$t is not a function" several times

Along with [Vue warn]: Error in mounted hook: "TypeError: this.$el.getElementsByClassName is not a function" and other errors which point to other components in the library which are now broken since the library is not using Vue-i18n.

Therefore I believe this PR is necessary because there are use cases such as mine where node modules built in vue using the same library will cause a conflict.

[jgribonvald]

If you want to reproduce the problem I've provided an example in #402
https://jsfiddle.net/jgribonvald/cmyk6Lua/
(Don't consider other errors)