Feature Request: no-ref-checks

[johnrom]

Hi all,

I started migrating a codebase from class-based to function-based and came across some silliness. I had completely missed converting some of the ref checks:

- const thing = this.thing;
+ const thing = useRef(props.thing);

// I missed this
- if (!thing) {
+ if (!thing.current) {

TypeScript considers !useRef(props.thing) to be perfectly valid since it may be testing for non-existence of the value even if it is not boolean. Thus, I'm thinking it might make sense to make sure a useRef's return value is never used as a boolean or condition at the react linter level. Not sure if it's possible with ESLint, but if so it could be a very useful rule which would catch a lot of bugs. Due to rules of hooks, it's not possible for the value to ever be undefined, so any checks for it are unnecessary and almost certainly indicate a bug.

[ljharb]

I think it's better for things that are specific to hooks to go in eslint-plugin-react-hooks, instead of here.

[johnrom]

I kind of agree, but it's not technically a hook rule but a type rule. A ref object is not necessarily hook-specific and the same rule could apply to createRef.

I also find it less likely they will expand the rules over there since it doesn't have to do with hook dependencies. I'll open an issue though and try it out.