unist-util-find

unist-util-find

unist utility to find a node.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • find(tree, condition)
  • TestFn
  • TestObj
  • TestStr
• Types
• Compatibility
• Security
• Related
• Contribute
• License

What is this?

This package is a utility that takes any unist (whether mdast, hast, etc) node and returns the first node that matches a given condition.

When should I use this?

This utility is the simplest way to find a single node in a tree.

For much more powerful tree walking, see unist-util-visit.

Install

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

npm install unist-util-find

In Deno with esm.sh:

import {find} from 'https://esm.sh/unist-util-find@2'

In browsers with esm.sh:

<script type="module">
  import {find} from 'https://esm.sh/unist-util-find@2?bundle'
</script>

Use

import {fromMarkdown} from 'mdast-util-from-markdown'
import {find} from 'unist-util-find'

const tree = fromMarkdown('Some _emphasis_, **strongness**, and `code`.')

// String condition:
console.log(find(tree, 'value'))

// Object condition:
console.log(find(tree, {value: 'emphasis'}))

// Function condition:
console.log(
  find(tree, function (node) {
    return node.type === 'inlineCode'
  })
)

Yields:

// string condition: 'value'
{
  type: 'text',
  value: 'Some ',
  position: {
    start: { line: 1, column: 1, offset: 0 },
    end: { line: 1, column: 6, offset: 5 }
  }
}

// object condition: { value: 'emphasis' }
{
  type: 'text',
  value: 'emphasis',
  position: {
    start: { line: 1, column: 7, offset: 6 },
    end: { line: 1, column: 15, offset: 14 }
  }
}

// function condition: function (node) { return node.type === 'inlineCode' }
{
  type: 'inlineCode',
  value: 'code',
  position: {
    start: { line: 1, column: 38, offset: 37 },
    end: { line: 1, column: 44, offset: 43 }
  }
}

API

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

find(tree, condition)

Find a node in tree matching condition.

Parameters

• tree (Node) — tree to search in
• condition (TestFn, TestObj, or TestStr) — condition used to test each node

Returns

The first node (Node) that matches condition, or undefined if no node matches

TestFn

Find the first node for which function returns true when passed node as argument (TypeScript type).

Parameters

• node (Node) — node to check

Returns

Whether node matches your condition (boolean).

TestObj

Find the first node that has matching values for all properties of object (TypeScript type).

Type

type TestObj = Record<string, unknown>;

TestStr

Find the first node with a truthy property matching string (TypeScript type).

Type

type TestStr = string;

Types

This package is fully typed with TypeScript. It exports the additional types TestFn, TestObj, and TestStr.

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@^2, compatible with Node.js 12.

Security

This project is safe.

Related

• unist-util-visit — visit nodes

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, organization, or community you agree to abide by its terms.

License

MIT © Richard Smith-Unna