require-default-props fails to parse Flow's read only/covariant prop types

[jsteiner]

Using Flow:

type Props = {
  +top?: SpacingType,
}

errors:

propType "+" is not required, but has no corresponding defaultProp declaration react/require-default-props

The + prefix is throwing off the parser, causing it to look for a prop + rather than the prop top.

Using eslint-plugin-react@^7.5.1

[HenriBeck]

@ljharb Couldn't this also be a rule?
Something like require-read-only-props when the project is using flow?

Seems like a good practice to me.

[ljharb]

@HenriBeck I suppose it could be; but this issue is about the default-props-match-prop-types rule not understanding covariant syntax (and presumably contravariant as well).

[alexzherdev]

I think the title here is incorrect - the error message in the OP refers to require-default-props.
Anyway, the fix for this is coming 😄