kryndex / unist-util-is

Utility to check if a node passes a test

unist-util-is

Unist utility to check if a node passes a test.

Installation

npm:

npm install unist-util-is

Usage

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

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

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

API

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

Parameters

• test (Function, string, or Node, optional) — When not given, checks if node is a Node. When string, works like passing function (node) {return node.type === test}. When object, checks that all keys in test are in node, and that they have (strictly) equal values.
• node (Node) — Node to check. false is returned;
• index (number, optional) — Position of node in parent;
• parent (Node, optional) — Parent of node;
• context (*, optiona) — Context object to invoke test with.

Returns

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

function test(node[, index, parent])

Parameters

• node (Node) — Node to test;
• index (number?) — Position of node in parent;
• parent (Node?) — Parent of node.

Context

* — The to is given context.

Returns

boolean? — Whether node matches.

License

MIT © Titus Wormer