When a getter is defined that does not define a setter, no recursive reactive is made.

[ts0307]

Version

2.5.17-beta.0

Reproduction link

https://jsfiddle.net/ts0307/pd8zr3sk/

Steps to reproduce

Run JSFiddle snippet

What is expected?

I expect, the result is shown as {"bar": "b"} instead of {"bar": "a"}

What is actually happening?

if ((!getter || setter) && arguments.length === 2) {
val = obj[key]
}

let childOb = !shallow && observe(val)

My example is that the data object defines that the getter does not define a setter, causing the above judgment to fail, val is not evaluated, and no recursive reactive is made.

[pkaminski]

FYI: Ignoring getters was done on purpose due to #7280. I added an exception for getter/setter pairs in #7828 to fix my own use case. I don't know whether ignoring pure getters is right or not, but either way it's clear that somebody will be unhappy.

[ts0307]

It seems that it is difficult to be compatible with all use cases.

[malaxiannv]

@ts0307 if a getter is defined, proving that the property is an accessor property. If an accessor property does not have a setter, that means the property cannot be set new Value, thus there is no need to make it be recursive reactive.

[shengrongchun]

why not?
let childOb = !shallow && observe(val) -->
get: function reactiveGetter () { const value = getter ? getter.call(obj) : val; childOb = !shallow && observe(value);