unified

Project: syntax-tree/unist-util-is

Package: unist-util-is@4.0.2

  1. Dependencies: 0·Dependents: 94
  2. unist utility to check if a node passes a test
  1. unist 103
  2. util 98
  3. utility 96
  4. tree 42
  5. unist-util 24
  6. node 21
  7. check 7
  8. test 6
  9. type 3
  10. is 2
  11. equal 2

unist-util-is

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unist utility to check if a node passes a test.

Install

npm:

npm install unist-util-is

Use

var is = require('unist-util-is')

var node = {type: 'strong'}
var parent = {type: 'paragraph', children: [node]}

function test(node, n) {
  return n === 5
}

is() // => false
is({children: []}) // => false
is(node) // => true
is(node, 'strong') // => true
is(node, 'emphasis') // => false

is(node, node) // => true
is(parent, {type: 'paragraph'}) // => true
is(parent, {type: 'strong'}) // => false

is(node, test) // => false
is(node, test, 4, parent) // => false
is(node, test, 5, parent) // => true

API

is(node[, test[, index, parent[, context]]])

Parameters
Returns

boolean — Whether test passed and node is a Node (object with type set to a non-empty string).

function test(node[, index, parent])

Parameters
Context

* — The to is given context.

Returns

boolean? — Whether node matches.

is.convert(test)

Create a test function from test, that can later be called with a node, index, and parent. Useful if you’re going to test many nodes, for example when creating a utility where something else passes an is-compatible test.

The created function is slightly faster because it expects valid input only. Therefore, passing invalid input, yields unexpected results.

Can also be accessed with require('unist-util-is/convert').

For example:

var u = require('unist-builder')
var convert = require('unist-util-is/convert')

var test = convert('leaf')

var tree = u('tree', [
  u('node', [u('leaf', '1')]),
  u('leaf', '2'),
  u('node', [u('leaf', '3'), u('leaf', '4')]),
  u('leaf', '5')
])

var leafs = tree.children.filter((child, index) => test(child, index, tree))

console.log(leafs)

Yields:

[{type: 'leaf', value: '2'}, {type: 'leaf', value: '5'}]

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 © Titus Wormer