False positives on react/jsx-props-no-multi-spaces with generic component

[luixo]

Setup: eslint 5.14.1 with @typescript-eslint/eslint-plugin 1.4.0
Minimal case:

<Foo<T> bar />

Error:
Expected only one space between "Foo" and "bar"

[ljharb]

It's very surprising that TS allows that; Foo<T> looks like a type, but the first item in a jsx element has to be a value.

[G-Rath]

It's very surprising that TS allows that

That's how you do generic JSX components in TypeScript.

[ljharb]

I'm still surprised they chose to deviate from the jsx spec for that.

[G-Rath]

But is it actually deviating from the spec, since it's never actually in the jsx when it gets compiled?

Like, I think its fuzzy on both sides - I can't think of a cleaner way they could have done it 😕

[ljharb]

Yes, it is. I'd say <Foo: Foo<T> /> would be much cleaner, and would stick to the "stuff after : is types" space.

That ship has obviously sailed, though.

[G-Rath]

I've not got the jsx spec in front of me, but why is it deviating from the spec to have a generic type straight after the component name, but not a colon?

[ljharb]

I suppose it’s more than in typescript itself, generics syntax only appears in type space, and in this case, it’s appearing in value space - so it seems inconsistent with typescript too.

[G-Rath]

Fair enough. What are the chances of getting a fix? Even if it has to be behind a typescript: true style option?

[ljharb]

I don't think it has to be behind an option; this change would be removing a false error only for typescript users.

I think a PR would be fine.