Version

2.7.10

Reproduction link

codepen.io

Steps to reproduce

Run the linked codepen with console open.

What is expected?

setup function from the component to be called before beforeCreate hook from the mixin as it is in Vue 3

What is actually happening?

beforeCreate function from the mixin is being called before the setup function from the component

Vue 3 lifecycle diagram shows setup being called before beforeCreate. Vue 2 diagram does not make any mention of the setup function. I would expect that the order of setup vs beforeCreate would be consistent between 2.7 and 3.x.

Minimal reproduction repo to observe vue 3 behavior: https://codepen.io/vetruvet/pen/LYmePyN

Why a mixin and why beforeCreate? This behavior is coming from a third-party library I don't control. The code I need to run in the setup function needs to access variables that are only available in the setup function and at the same time needs to run before that 3rd-party code in the beforeCreate hook.

Looking at the where the hooks are called, beforeCreate is indeed called before setup (https://github.com/vuejs/vue/blob/v2.7.10/src/core/instance/init.ts#L62 and two lines down initState calls initSetup)