Version

3.2.0-beta.8

Reproduction link

https://codesandbox.io/s/frosty-sun-471ok?file=/src/main.js

Steps to reproduce

look console.log

What is expected?

get value

What is actually happening?

not get value

Use this: https://v3.vuejs.org/api/application-config.html#globalproperties

Please, next time consider using the forum, the Discord server or StackOverflow for questions first. But feel free to come back and open an issue if it turns out to be a bug 🙂

https://codesandbox.io/s/frosty-sun-471ok?file=/src/main.js please look at the code again, thanks @posva Is this intentional? we can't use Object.prototype with vue together?

use Object.defineProperty to define the property on the prototype.

use Object.defineProperty to define the property on the prototype.

It does work but why, use Object.propotype will error is it a bug?

you are adding a property to all objects, it is possible that you broke code that did not expect to have that property there.

@posva is this a bug? Can you reconsider reopen ? thank you

I don't think this is a bug because extending Object.prototype should be avoided at all costs. It will break any library that iterates through keys with for in, which can be used for performance reasons.

This is not considered a bug because mutating Object.prototype is something you should never do in modern JavaScript. While Vue 3 can go out of its way to "support" it, it just incurs performance overhead on all other users (99.9%) for a case where there is no actual benefits.

https://github.com/vuejs/vue-next/pull/4361#issuecomment-900430368