Vue.set Api strange behavior if path is a numerical string

[TheDadycool]

Version

2.3.4

Reproduction link

https://jsfiddle.net/v0dbnvv0/1/

Steps to reproduce

Vue.set(array, "indexInTheArrayInString", value) is not working as expected compare to Vue.set(array, "indexInTheArrayInNumericForm", value)

What is expected?

Both version working the same i suppose?

What is actually happening?

Watcher on the value are not triggered even if the value is correctly changed in the model

---

My currently fixed in my code:
export function AdvVueSet(obj, path, value) {
if (!isNaN(path)) {
path = +path;
}
Vue.set(obj, path, value);
}

[defcc]

I think maybe there should be an improvement, as we could access and assign array item via string type index. In fact, a[1] is equal to a['1']. Refer http://www.ecma-international.org/ecma-262/5.1/#sec-15.4

We could check the key, and try to convert it to a number type.

vue/src/core/observer/index.js

Line 192 in 1648adb

if (Array.isArray(target) && typeof key === 'number') {

[yyx990803]

Probably just check if the string is an integer because it has to be an index.

[defcc]

Thanks @Peter-WF