watch reactive array callback called with array of undefined

[tanhauhau]

Version

3.0.0-rc.2

Reproduction link

https://codesandbox.io/s/fervent-sun-87su3?file=/src/index.js

Steps to reproduce

watch a reactive array, the callback function is called with array of undefined

What is expected?

callback function is called with array of undefined

What is actually happening?

callback function is called with the reactive array value

[posva]

as the warning suggests, you need to use a function: watch(() => array with reactive. You will also need { deep: true } to track changes inside of the array