New rule suggestion: no-access-state-in-setstate

[zerkms]

This is the same as https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/no-access-state-in-setstate.md

The purpose: to deny using this.state inside this.setState call.

Why: Given this.setState mutates the state asynchronously it's extremely easy to introduce a subtle bug when in 2 sequential calls one relies on a particular this.state state. And if those this.setState calls are in different functions and spatially not even close the problem might be really challenging to debug.

[karfau]

In #80 it was suggested for this rule to have an option for only allowing the functional way of setting state instead of making this a standalone rule. this option could allow for quite a performance boost in detecting failing cases.

[cheeZery]

Oh my, I already submitted a PR (#190) for this a while ago but somehow managed to link the wrong issue back then.. changed that now :)

[karfau]

Since #190 was reverted in #211 this issue has not been fixed.

[cheeZery]

In case your wondering about the progress of this issue: I started working on the typed rule but ran into some problems and now need a bit of help, #190 (comment) :-) Feel free to share your knowledge ♥

[adidahiya]

This suggestion is still a good idea, but it should be migrated to an eslint rule. See #210

[karfau]

no need to migrate it, the idea came from an eslint rule, see description