@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.event object? instance of MouseEvent, KeyboardEvent
  • 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.event object? instance of MouseEvent, KeyboardEvent
  • 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.event object? instance of MouseEvent, KeyboardEvent
  • 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.event object? instance of MouseEvent, KeyboardEvent
  • 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	Partially supported	Matching with MathML is not yet supported.
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	✓	Enabled if a mousedown / pointerdown event is passed as an option.
E:hover	✓	Enabled if a mouseover / pointerover event is passed as an option.
E:focus	✓
E:focus‑within	✓
E:focus‑visible	✓	Enabled if a keydown event is passed as an option.
E:open E:closed	Partially supported	Matching with <select>, e.g. select:open, is not supported.
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‑valid 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
E:host	✓
E:host(s)	✓
E:host‑context(s)	✓
E:popover-open	✓
E:state(v)	✓	*1
E:host(:state(v))	✓	*1

*1: ElementInternals.states, i.e. CustomStateSet, is not implemented in jsdom, so you need to apply a patch in the custom element constructor.

class LabeledCheckbox extends window.HTMLElement {
  #internals;
  constructor() {
    super();
    this.#internals = this.attachInternals();
    // patch CustomStateSet
    if (!this.#internals.states) {
      this.#internals.states = new Set();
    }
    this.addEventListener('click', this._onClick.bind(this));
  }
  get checked() {
    return this.#internals.states.has('checked');
  }
  set checked(flag) {
    if (flag) {
      this.#internals.states.add('checked');
    } else {
      this.#internals.states.delete('checked');
    }
  }
  _onClick(event) {
    this.checked = !this.checked;
  }
}

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 domSelector = new DOMSelector(window);

    const matches = domSelector.matches.bind(domSelector);
    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);
    };

    const closest = domSelector.closest.bind(domSelector);
    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);
    };

    const querySelector = domSelector.querySelector.bind(domSelector);
    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);
    };

    const querySelectorAll = domSelector.querySelectorAll.bind(domSelector);
    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

See benchmark for the latest results.

F: Failed because the selector is not supported or the result was incorrect.

matches()

Selector	jsdom v24.1.1 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: matches('.content')	957,875 ops/sec ±0.97%	7,248 ops/sec ±0.58%	7,435 ops/sec ±0.63%	811,680 ops/sec ±1.32%	jsdom is the fastest and 1.2 times faster than patched-jsdom.
compound selector: matches('p.content[id]:is(:last-child, :only-child)')	591,790 ops/sec ±1.01%	7,003 ops/sec ±0.84%	7,118 ops/sec ±0.77%	400,189 ops/sec ±0.29%	jsdom is the fastest and 1.5 times faster than patched-jsdom.
compound selector: matches('p.content[id]:is(:invalid-nth-child, :only-child)')	F	7,018 ops/sec ±0.53%	F	74,449 ops/sec ±0.90%	patched-jsdom is the fastest.
compound selector: matches('p.content[id]:not(:is(.foo, .bar))')	471,272 ops/sec ±0.38%	6,777 ops/sec ±0.57%	7,067 ops/sec ±0.54%	338,117 ops/sec ±1.49%	jsdom is the fastest and 1.4 times faster than patched-jsdom.
complex selector: matches('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	151,368 ops/sec ±1.59%	F	4,723 ops/sec ±0.69%	124,920 ops/sec ±1.31%	jsdom is the fastest and 1.2 times faster than patched-jsdom.
complex selector: matches('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner:has(> .content)')	F	F	4,610 ops/sec ±0.68%	41,718 ops/sec ±2.02%	patched-jsdom is the fastest.
complex selector within logical pseudo-class: matches(':is(.box > .content, .block > .content)')	411,511 ops/sec ±1.61%	F	4,958 ops/sec ±0.35%	333,788 ops/sec ±1.24%	jsdom is the fastest and 1.2 times faster than patched-jsdom.

closest()

Selector	jsdom v24.1.1 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: closest('.container')	370,268 ops/sec ±1.72%	7,123 ops/sec ±0.63%	7,399 ops/sec ±0.75%	339,853 ops/sec ±1.49%	jsdom is the fastest and 1.1 times faster than patched-jsdom.
compound selector: closest('div.container[id]:not(.foo, .box)')	133,846 ops/sec ±1.40%	F	6,977 ops/sec ±0.61%	124,635 ops/sec ±1.41%	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')	139,233 ops/sec ±1.93%	F	4,648 ops/sec ±0.87%	119,991 ops/sec ±0.23%	jsdom is the fastest and 1.2 times faster than patched-jsdom.
complex selector: closest('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner:has(> .content)')	F	F	4,618 ops/sec ±0.76%	37,743 ops/sec ±1.86%	patched-jsdom is the fastest.
complex selector within logical pseudo-class: closest(':is(.container > .content, .container > .box)')	196,742 ops/sec ±1.46%	4,454 ops/sec ±1.05%	4,846 ops/sec ±0.61%	176,010 ops/sec ±1.34%	jsdom is the fastest and 1.1 times faster than patched-jsdom.

querySelector()

Selector	jsdom v24.1.1 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: querySelector('.content')	32,150 ops/sec ±1.48%	8,957 ops/sec ±1.16%	8,707 ops/sec ±0.68%	29,777 ops/sec ±1.81%	jsdom is the fastest and 1.1 times faster than patched-jsdom.
compound selector: querySelector('p.content[id]:is(:last-child, :only-child)')	10,249 ops/sec ±1.33%	8,618 ops/sec ±1.28%	8,311 ops/sec ±0.60%	9,614 ops/sec ±1.31%	jsdom is the fastest and 1.1 times faster than patched-jsdom.
complex selector: querySelector('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	230 ops/sec ±1.26%	F	1,265 ops/sec ±1.58%	268 ops/sec ±1.23%	linkedom is the fastest and 4.7 times faster than patched-jsdom. patched-jsdom is 1.2 times faster than jsdom.
complex selector: querySelector('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner:has(> .content)')	F	F	1,501 ops/sec ±1.51%	706 ops/sec ±2.25%	linkedom is the fastest and 2.1 times faster than patched-jsdom.
complex selector within logical pseudo-class: querySelector(':is(.box > .content, .block > .content)')	3,305 ops/sec ±1.72%	F	8,133 ops/sec ±0.71%	154,046 ops/sec ±2.15%	patched-jsdom is the fastest. patched-jsdom is 46.6 times faster than jsdom.

querySelectorAll()

Selector	jsdom v24.1.1 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: querySelectorAll('.content')	3,099 ops/sec ±1.08%	785 ops/sec ±1.79%	1,145 ops/sec ±1.41%	3,032 ops/sec ±0.28%	jsdom is the fastest and 1.0 times faster than patched-jsdom.
compound selector: querySelectorAll('p.content[id]:is(:last-child, :only-child)')	1,018 ops/sec ±0.34%	731 ops/sec ±1.57%	1,155 ops/sec ±1.23%	995 ops/sec ±1.18%	linkedom is the fastest and 1.2 times faster than patched-jsdom. jsdom is 1.0 times faster than patched-jsdom.
complex selector: querySelectorAll('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	231 ops/sec ±1.23%	F	420 ops/sec ±1.37%	276 ops/sec ±0.23%	linkedom is the fastest and 1.5 times faster than patched-jsdom. patched-jsdom is 1.2 times faster than jsdom.
complex selector: querySelectorAll('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner:has(> .content)')	F	F	447 ops/sec ±1.41%	801 ops/sec ±2.65%	patched-jsdom is the fastest.
complex selector within logical pseudo-class: querySelectorAll(':is(.box > .content, .block > .content)')	322 ops/sec ±0.40%	F	508 ops/sec ±1.40%	767 ops/sec ±1.66%	patched-jsdom is the fastest. patched-jsdom is 2.4 times faster than jsdom.

Acknowledgments

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

• CSSTree
• selery
• jsdom
• nwsapi

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Copyright (c) 2023 asamuzaK (Kazz)