Unist-builder NPM

unist-builder

unist utility to create trees with ease.

What is this?

This package is a hyperscript interface (like createElement from React and h from Vue and such) to help with creating unist trees.

When should I use this?

You can use this utility in your project when you generate syntax trees with code. It helps because it replaces most of the repetition otherwise needed in a syntax tree with function calls.

You can instead use hastscript or xastscript when creating hast (HTML) or xast (XML) nodes.

Install

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

npm install unist-builder

In Deno with esm.sh:

import {u} from 'https://esm.sh/unist-builder@4'

In browsers with esm.sh:

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

Use

import {u} from 'unist-builder'

const tree = u('root', [
  u('subtree', {id: 1}),
  u('subtree', {id: 2}, [
    u('node', [u('leaf', 'leaf 1'), u('leaf', 'leaf 2')]),
    u('leaf', {id: 3}, 'leaf 3'),
    u('void', {id: 4})
  ])
])

console.dir(tree, {depth: undefined})

…yields:

{
  type: 'root',
  children: [
    {type: 'subtree', id: 1},
    {
      type: 'subtree',
      id: 2,
      children: [
        {
          type: 'node',
          children: [
            {type: 'leaf', value: 'leaf 1'},
            {type: 'leaf', value: 'leaf 2'}
          ]
        },
        {type: 'leaf', id: 3, value: 'leaf 3'},
        {type: 'void', id: 4}
      ]
    }
  ]
}

API

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

`u(type[, props][, children|value])`

Build a node.

Signatures

u(type[, props], children) — create a parent (Parent)
u(type[, props], value) — create a literal (Literal)
u(type[, props]) — create a void node (neither parent not literal)

Parameters

type (string) — node type
props (Record<string, unknown>) — fields assigned to node
children (Array<Node>) — children of node
value (*) — value of node (cast to string)

Returns

Built node (Node).

`ChildrenOrValue`

List to use as children or value to use as value (TypeScript type).

Type

type ChildrenOrValue = Array<Node> | string

`Props`

Other fields to add to the node (TypeScript type).

Type

export type Props = Record<string, unknown>

Types

This package is fully typed with TypeScript. It exports the additional types ChildrenOrValue and Props.

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-builder@^4, compatible with Node.js 16.