unist-util-find-all-before
Version:
unist utility to find nodes before another node
75 lines (74 loc) • 1.98 kB
TypeScript
/**
* Find the nodes in `parent` before another `node` or before an index, that
* pass `test`.
*
* @param parent
* Parent node.
* @param index
* Child node or index.
* @param [test=undefined]
* Test for child to look for (optional).
* @returns
* Children (matching `test`, if given).
*/
export const findAllBefore: (<
Kind extends import('unist').Parent,
Check extends Test
>(
parent: Kind,
index: number | Child<Kind>,
test: Check
) => Matches<Child<Kind>, Check>[]) &
(<Kind_1 extends import('unist').Parent>(
parent: Kind_1,
index: number | Child<Kind_1>,
test?: null | undefined
) => Child<Kind_1>[])
export type UnistNode = import('unist').Node
export type UnistParent = import('unist').Parent
/**
* Test from `unist-util-is`.
*
* Note: we have remove and add `undefined`, because otherwise when generating
* automatic `.d.ts` files, TS tries to flatten paths from a local perspective,
* which doesn’t work when publishing on npm.
*/
export type Test = Exclude<import('unist-util-is').Test, undefined> | undefined
/**
* Get the value of a type guard `Fn`.
*/
export type Predicate<Fn, Fallback> = Fn extends (
value: any
) => value is infer Thing
? Thing
: Fallback
/**
* Check whether a node matches a primitive check in the type system.
*/
export type MatchesOne<Value, Check> = Check extends null | undefined
? Value
: Value extends {
type: Check
}
? Value
: Value extends Check
? Value
: Check extends Function
? Predicate<Check, Value> extends Value
? Predicate<Check, Value>
: never
: never
/**
* Check whether a node matches a check in the type system.
*/
export type Matches<Value, Check> = Check extends Array<any>
? MatchesOne<Value, Check[keyof Check]>
: MatchesOne<Value, Check>
/**
* Collect nodes that can be parents of `Child`.
*/
export type Child<Kind extends import('unist').Node> = Kind extends {
children: (infer Child_1)[]
}
? Child_1
: never