Vue 3 Reactivity: Q & A with Evan You

After learning how reactivity was written in Vue 2 and then in Vue 3 I was left with a couple of questions. Luckily, I had an opportunity to sit down with Evan You, the author of Vue, and ask him in person.

Questions we cover include:

• In Vue 2 Reactivity we used depend and notify for recording and playing back effects, and in Vue 3 we use track and trigger, why the change?
• In Vue 2 Reactivity Dep is a class with subscribers, and in Vue 3 dep is simply a Set. Why the change?
• How did you end up with the effect storage solution in Vue 3? i.e. targetMap and depsMap
• Why use Object Accessors with ref rather than just re-using reactive?
• Using Reflect & Proxy in Vue 3 allows us to add properties later that we want to be reactive, but what other benefits does this give us?