Add types about unist-util-visit HOT 7 CLOSED

https://github.com/syntax-tree/unist-util-visit/pull/16/files#diff-fbc098e48a28691a544d0b13581a96af should give a better picture of how this can work cross-project.
There are tests for a remark heading node and a rehype element node.

from unist-util-visit.

Released as well!

from unist-util-visit.

Ideally when a function is passed as a test, it should be able to define a type predicate, and verify that the type passed to the visitor matches
https://www.typescriptlang.org/docs/handbook/advanced-types.html#using-type-predicates

from unist-util-visit.

Also ideally if a string is passed for a test, TypeScript should verify that the string value matches the type of the node.
For example

interface HeadingNode extends ParentNode {
  type: 'heading'
  depth: number
}

// valid
unistUntiVisit(tree, 'heading', (node: HeadingNode) => {...})

// not valid
unistUntiVisit(tree, 'not-a-heading', (node: HeadingNode) => {...})

from unist-util-visit.

How would type work with the different syntax es, and with custom nodes?

from unist-util-visit.

My goal is to keep it generic.
The only requirement that I am aware of is that what gets passed as tree and what gets passed as node, must extend unist Node. In that they must have a typeattribute.
Everything else should be flexible enough to support unist, mdast, mdxast, hast and redot.

from unist-util-visit.

Perfect!

from unist-util-visit.