fix: reconcile the overridden prototype of component and _Vue mocks and mixins

[kuitos]

fixed #889
@eddyerburgh please make a review

[kuitos]

@eddyerburgh could you please donate some time to review it?

[eddyerburgh]

Yes, I was intending to look at it today 👍

[eddyerburgh]

I believe this would mutate components:

const CompA = Vue.extend()
const CompB = CompA.extend().extend()
const savedProto = CompA.prototype.__proto__
const rootProto = CompB.prototype.__proto__.__proto__
Object.setPrototypeOf(rootProto, null)

console.log(savedProto === CompA.prototype.__proto__) // false

[kuitos]

yes it could if you set the proto of rootProto to be null.
But here we actually did was Object.setPrototypeOf(rootProto, _Vue.prototype)

const rootProto = CompB.prototype.__proto__.__proto__
Object.setPrototypeOf(rootProto, Vue.prototype)

console.log(savedProto === CompA.prototype.__proto__) // true

[eddyerburgh]

If you set it to _Vue then I think it would still mutate the protoype, it just wouldn't be as severe:

const CompA = Vue.extend()
const CompB = CompA.extend().extend()
const _Vue = Vue.extend()

const savedProto = CompA.prototype.__proto__
const rootProto = CompB.prototype.__proto__.__proto__
Object.setPrototypeOf(rootProto, _Vue.prototype)

console.log(savedProto === CompA.prototype.__proto__) // false

[kuitos]

I agree with what you concerned about, I will add an unit test and find a way to guarantee the super component immutably.
What do you think? Any suggestion? :)

[eddyerburgh]

That would be great, I don't have any suggestions unfortunately. I spent some time two weeks ago investigating, but I couldn't find a solution that didn't mutate the original components