@asamuzakjp/dom-selector

DOM Selector

A CSS selector engine.

Install

npm i @asamuzakjp/dom-selector

Usage

import { DOMSelector } from '@asamuzakjp/dom-selector';
import { JSDOM } from 'jsdom';

const { window } = new JSDOM();
const {
  closest, matches, querySelector, querySelectorAll
} = new DOMSelector(window);

matches(selector, node, opt)

matches - same functionality as Element.matches()

Parameters

• selector string CSS selector
• node object Element node
• opt object? options
  • opt.noexcept boolean? no exception
  • opt.warn boolean? console warn e.g. unsupported pseudo-class

Returns boolean true if matched, false otherwise

closest(selector, node, opt)

closest - same functionality as Element.closest()

Parameters

• selector string CSS selector
• node object Element node
• opt object? options
  • opt.noexcept boolean? no exception
  • opt.warn boolean? console warn e.g. unsupported pseudo-class

Returns object? matched node

querySelector(selector, node, opt)

querySelector - same functionality as Document.querySelector(), DocumentFragment.querySelector(), Element.querySelector()

Parameters

• selector string CSS selector
• node object Document, DocumentFragment or Element node
• opt object? options
  • opt.noexcept boolean? no exception
  • opt.warn boolean? console warn e.g. unsupported pseudo-class

Returns object? matched node

querySelectorAll(selector, node, opt)

querySelectorAll - same functionality as Document.querySelectorAll(), DocumentFragment.querySelectorAll(), Element.querySelectorAll()
NOTE: returns Array, not NodeList

Parameters

• selector string CSS selector
• node object Document, DocumentFragment or Element node
• opt object? options
  • opt.noexcept boolean? no exception
  • opt.warn boolean? console warn e.g. unsupported pseudo-class

Returns Array<(object | undefined)> array of matched nodes

Supported CSS selectors

Pattern	Supported	Note
*	✓
ns|E	✓
*|E	✓
|E	✓
E	✓
E:not(s1, s2, …)	✓
E:is(s1, s2, …)	✓
E:where(s1, s2, …)	✓
E:has(rs1, rs2, …)	✓
E.warning	✓
E#myid	✓
E[foo]	✓
E[foo="bar"]	✓
E[foo="bar" i]	✓
E[foo="bar" s]	✓
E[foo~="bar"]	✓
E[foo^="bar"]	✓
E[foo$="bar"]	✓
E[foo*="bar"]	✓
E[foo|="en"]	✓
E:defined	Unsupported
E:dir(ltr)	✓
E:lang(en)	Partially supported	Comma-separated list of language codes, e.g. :lang(en, fr), is not yet supported.
E:any‑link	✓
E:link	✓
E:visited	✓	Returns false or null to prevent fingerprinting.
E:local‑link	✓
E:target	✓
E:target‑within	✓
E:scope	✓
E:current	Unsupported
E:current(s)	Unsupported
E:past	Unsupported
E:future	Unsupported
E:active	Unsupported
E:hover	Unsupported
E:focus	✓
E:focus‑within	✓
E:focus‑visible	Unsupported
E:enabled E:disabled	✓
E:read‑write E:read‑only	✓
E:placeholder‑shown	✓
E:default	✓
E:checked	✓
E:indeterminate	✓
E:valid E:invalid	✓
E:required E:optional	✓
E:blank	Unsupported
E:user‑invalid	Unsupported
E:root	✓
E:empty	✓
E:nth‑child(n [of S]?)	✓
E:nth‑last‑child(n [of S]?)	✓
E:first‑child	✓
E:last‑child	✓
E:only‑child	✓
E:nth‑of‑type(n)	✓
E:nth‑last‑of‑type(n)	✓
E:first‑of‑type	✓
E:last‑of‑type	✓
E:only‑of‑type	✓
E F	✓
E > F	✓
E + F	✓
E ~ F	✓
F || E	Unsupported
E:nth‑col(n)	Unsupported
E:nth‑last‑col(n)	Unsupported
:host	✓
:host(s)	✓
:host‑context(s)	✓

Monkey patch jsdom

import { DOMSelector } from '@asamuzakjp/dom-selector';
import { JSDOM } from 'jsdom';

const dom = new JSDOM('', {
  runScripts: 'dangerously',
  url: 'http://localhost/',
  beforeParse: window => {
    const {
      closest, matches, querySelector, querySelectorAll
    } = new DOMSelector(window);
    window.Element.prototype.matches = function (...args) {
      if (!args.length) {
        throw new window.TypeError('1 argument required, but only 0 present.');
      }
      const [selector] = args;
      return matches(selector, this);
    };
    window.Element.prototype.closest = function (...args) {
      if (!args.length) {
        throw new window.TypeError('1 argument required, but only 0 present.');
      }
      const [selector] = args;
      return closest(selector, this);
    };
    window.Document.prototype.querySelector = function (...args) {
      if (!args.length) {
        throw new window.TypeError('1 argument required, but only 0 present.');
      }
      const [selector] = args;
      return querySelector(selector, this);
    };
    window.DocumentFragment.prototype.querySelector = function (...args) {
      if (!args.length) {
        throw new window.TypeError('1 argument required, but only 0 present.');
      }
      const [selector] = args;
      return querySelector(selector, this);
    };
    window.Element.prototype.querySelector = function (...args) {
      if (!args.length) {
        throw new window.TypeError('1 argument required, but only 0 present.');
      }
      const [selector] = args;
      return querySelector(selector, this);
    };
    window.Document.prototype.querySelectorAll = function (...args) {
      if (!args.length) {
        throw new window.TypeError('1 argument required, but only 0 present.');
      }
      const [selector] = args;
      return querySelectorAll(selector, this);
    };
    window.DocumentFragment.prototype.querySelectorAll = function (...args) {
      if (!args.length) {
        throw new window.TypeError('1 argument required, but only 0 present.');
      }
      const [selector] = args;
      return querySelectorAll(selector, this);
    };
    window.Element.prototype.querySelectorAll = function (...args) {
      if (!args.length) {
        throw new window.TypeError('1 argument required, but only 0 present.');
      }
      const [selector] = args;
      return querySelectorAll(selector, this);
    };
  }
});

Performance

matches()

Selector	jsdom v24.0.0 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: matches('.content')	2,645,575 ops/sec ±1.15%	1,643,332 ops/sec ±0.97%	646,061 ops/sec ±0.95%	2,374,666 ops/sec ±0.85%	jsdom is the fastest and 1.1 times faster than patched-jsdom.
compound selector: matches('p.content[id]:only-child')	1,197,421 ops/sec ±0.20%	443,001 ops/sec ±0.39%	300,277 ops/sec ±0.26%	952,967 ops/sec ±0.91%	jsdom is the fastest and 1.3 times faster than patched-jsdom.
complex selector: matches('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	162,015 ops/sec ±0.29%	N/A	73,881 ops/sec ±0.13%	143,422 ops/sec ±0.26%	jsdom is the fastest and 1.1 times faster than patched-jsdom.

closest()

Selector	jsdom v24.0.0 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: closest('.container')	541,108 ops/sec ±0.68%	352,175 ops/sec ±1.94%	388,746 ops/sec ±2.30%	533,387 ops/sec ±1.68%	jsdom is the fastest and 1.0 times faster than patched-jsdom.
compound selector: closest('div.container[id]:not(.box)')	211,165 ops/sec ±1.27%	77,934 ops/sec ±1.84%	163,773 ops/sec ±2.17%	195,860 ops/sec ±1.43%	jsdom is the fastest and 1.1 times faster than patched-jsdom.
complex selector: closest('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	153,514 ops/sec ±1.41%	N/A	72,422 ops/sec ±0.29%	139,221 ops/sec ±0.43%	jsdom is the fastest and 1.1 times faster than patched-jsdom.

querySelector()

Selector	jsdom v24.0.0 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: querySelector('.content')	3,482 ops/sec ±0.97%	360,089 ops/sec ±1.32%	321,631 ops/sec ±1.54%	75,390 ops/sec ±0.99%	happydom is the fastest and 4.8 times faster than patched-jsdom. patched-jsdom is 21.6 times faster than jsdom.
compound selector: querySelector('p.content[id]:only-child')	1,297 ops/sec ±1.22%	365,512 ops/sec ±2.03%	253,436 ops/sec ±1.82%	75,888 ops/sec ±0.81%	happydom is the fastest and 4.8 times faster than patched-jsdom. patched-jsdom is 58.5 times faster than jsdom.
complex selector: querySelector('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	216 ops/sec ±1.94%	N/A	1,315 ops/sec ±1.46%	770 ops/sec ±1.69%	linkedom is the fastest and 1.7 times faster than patched-jsdom. patched-jsdom is 3.6 times faster than jsdom.

querySelectorAll()

Selector	jsdom v24.0.0 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: querySelectorAll('.content')	3,250 ops/sec ±0.43%	752 ops/sec ±1.85%	1,175 ops/sec ±1.45%	3,391 ops/sec ±1.02%	patched-jsdom is the fastest. patched-jsdom is 1.0 times faster than jsdom.
compound selector: querySelectorAll('p.content[id]:only-child')	1,252 ops/sec ±1.46%	913 ops/sec ±1.60%	1,027 ops/sec ±1.08%	1,223 ops/sec ±1.12%	jsdom is the fastest and 1.0 times faster than patched-jsdom.
complex selector: querySelectorAll('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	227 ops/sec ±1.35%	N/A	434 ops/sec ±1.37%	754 ops/sec ±1.86%	patched-jsdom is the fastest. patched-jsdom is 3.3 times faster than jsdom.

Acknowledgments

The following resources have been of great help in the development of the DOM Selector.

• CSSTree
• selery
• jsdom

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Copyright (c) 2023 asamuzaK (Kazz)