rule proposal: force boolean props to be auxiliary verb's

[alexreardon]

Our code base is looking to enforce the use of auxiliary verb's (eg is, was, should and so on) for boolean props

propTypes = {
  // not allowed
  selected: PropTypes.boolean,

  // allowed
  isSelected: PropTypes.boolean 
}

I was going to write a custom babel plugin for this but I thought it might be a general enough case to put in this repo. I would be happy to write the rule and associated tests.

Cheers

[lencioni]

I'd be happy to help review a PR that adds this. What do you plan to call it?

It would also be nice to have an option to enforce the opposite.

[alexreardon]

Sounds good!

[ljharb]

Before making a PR, we may want to think about the schema a bit.

For example, I can see wanting exceptions - ie, "require auxiliary verbs for boolean props, except for props that have these names", or "forbid auxiliary verbs for boolean props, except for props that have these names". I can also see wanting to include additional PropTypes in this - in other words, if I have a custom propTypes that is in fact a boolean but has additional validation, I might want the same require/forbid behavior.

It's very important to think about how this rule can be extended, even if the initial PR doesn't need to contain all those features.

[alexreardon]

Good thinking. In its most general sense this rule is suffix conventions for particular prop types - built in or custom. With the suffix being a limited set of words. In the case of auxiliary verbs it would be 'is, can, should...' and so on.

[ljharb]

What schema do you have in mind for allowing the user to specify the propTypes? What about to exempt specific prop names from the rule?

[alexzherdev]

I think this has been achieved in boolean-prop-naming via #1264.