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unist-util-find-before

unist utility to find a node before another node.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • findBefore(parent, node|index[, test])
• Types
• Compatibility
• Related
• Contribute
• License

What is this?

This is a tiny utility that you can use to find a node before another node or before an index in a parent.

When should I use this?

This is super tiny. You can of course do it yourself. But this helps when integrating with the rest of unified and unist.

Install

This package is ESM only. In Node.js (version 16+), install with npm:

npm install unist-util-find-before

In Deno with esm.sh:

import {findBefore} from 'https://esm.sh/unist-util-find-before@4'

In browsers with esm.sh:

<script type="module">
  import {findBefore} from 'https://esm.sh/unist-util-find-before@4?bundle'
</script>

Use

import {u} from 'unist-builder'
import {findBefore} from 'unist-util-find-before'

const tree = u('tree', [
  u('leaf', 'leaf 1'),
  u('parent', [u('leaf', 'leaf 2'), u('leaf', 'leaf 3')]),
  u('leaf', 'leaf 4'),
  u('parent', [u('leaf', 'leaf 5')]),
  u('leaf', 'leaf 6'),
  u('empty'),
  u('leaf', 'leaf 7')
])

const empty = tree.children[5]

console.log(findBefore(tree, empty, 'parent'))

Yields:

{type: 'parent', children: [{type: 'leaf', value: 'leaf 5'}]}

API

This package exports the identifier findBefore. There is no default export.

findBefore(parent, node|index[, test])

Find the first node in parent before another node or before an index, that passes test.

Parameters

• parent (Node) — parent node
• index (number) — index of child in parent
• child (Node) — child in parent
• test (Test) — unist-util-is-compatible test

Returns

Child of parent (Node) or undefined.

Types

This package is fully typed with TypeScript. It exports no additional types (types for the test are in unist-util-is).

Compatibility

Projects maintained by the unified collective are compatible with maintained versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, unist-util-find-before@^4, compatible with Node.js 16.

Related

• unist-util-find-after — find a node after another node
• unist-util-find-all-after — find all nodes after another node
• unist-util-find-all-before — find all nodes before another node
• unist-util-find-all-between — find all nodes between two nodes
• unist-util-visit — walk the tree
• unist-util-visit-parents — walk the tree with a stack of parents
• unist-util-filter — create a new tree with all nodes that pass a test
• unist-util-map — create a new tree with all nodes mapped by a given function
• unist-util-flatmap — create a new tree by mapping (to an array) by a given function
• unist-util-remove — remove nodes from a tree that pass a test
• unist-util-select — select nodes with CSS-like selectors

Contribute

See contributing.md in syntax-tree/.github for ways to get started. See support.md for ways to get help.

This project has a Code of Conduct. By interacting with this repository, organisation, or community you agree to abide by its terms.

License

MIT © Titus Wormer