@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 - equivalent to 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 - equivalent to 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 - equivalent to Document.querySelector(), DocumentFragment.querySelector() and 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 - equivalent to Document.querySelectorAll(), DocumentFragment.querySelectorAll() and 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	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	✓
E:hover	✓
E:focus	✓
E:focus‑within	✓
E:focus‑visible	✓
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 v25.0.0 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: matches('.content')	937,822 ops/sec ±0.50%	7,910,671 ops/sec ±0.27%	8,620 ops/sec ±0.75%	772,780 ops/sec ±0.30%	happydom is the fastest and 10.2 times faster than patched-jsdom. jsdom is 1.2 times faster than patched-jsdom.
compound selector: matches('p.content[id]:is(:last-child, :only-child)')	572,176 ops/sec ±0.38%	7,693,760 ops/sec ±1.88%	8,257 ops/sec ±0.63%	402,508 ops/sec ±0.21%	happydom is the fastest and 19.1 times faster than patched-jsdom. jsdom is 1.4 times faster than patched-jsdom.
compound selector: matches('p.content[id]:is(:invalid-nth-child, :only-child)')	F	6,987,723 ops/sec ±0.39%	F	74,756 ops/sec ±1.26%	happydom is the fastest and 93.5 times faster than patched-jsdom.
compound selector: matches('p.content[id]:not(:is(.foo, .bar))')	455,833 ops/sec ±1.90%	6,645,611 ops/sec ±1.63%	8,205 ops/sec ±1.12%	326,773 ops/sec ±1.38%	happydom is the fastest and 20.3 times faster than patched-jsdom. jsdom is 1.4 times faster than patched-jsdom.
complex selector: matches('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	144,430 ops/sec ±1.65%	F	5,445 ops/sec ±1.00%	121,298 ops/sec ±1.34%	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	5,337 ops/sec ±0.86%	17,419 ops/sec ±2.05%	patched-jsdom is the fastest.
complex selector within logical pseudo-class: matches(':is(.box > .content, .block > .content)')	398,206 ops/sec ±0.51%	F	5,719 ops/sec ±0.84%	326,625 ops/sec ±1.25%	jsdom is the fastest and 1.2 times faster than patched-jsdom.

closest()

Selector	jsdom v25.0.0 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: closest('.container')	357,783 ops/sec ±1.70%	2,319,384 ops/sec ±0.92%	8,581 ops/sec ±0.84%	328,849 ops/sec ±1.31%	happydom is the fastest and 7.1 times faster than patched-jsdom. jsdom is 1.1 times faster than patched-jsdom.
compound selector: closest('div.container[id]:not(.foo, .box)')	131,236 ops/sec ±0.73%	F	8,052 ops/sec ±0.95%	119,653 ops/sec ±1.44%	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')	137,291 ops/sec ±0.17%	F	5,483 ops/sec ±0.36%	116,733 ops/sec ±0.21%	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	5,354 ops/sec ±0.87%	14,363 ops/sec ±1.58%	patched-jsdom is the fastest.
complex selector within logical pseudo-class: closest(':is(.container > .content, .container > .box)')	190,643 ops/sec ±1.69%	2,819,109 ops/sec ±1.22%	5,732 ops/sec ±0.34%	169,772 ops/sec ±1.48%	happydom is the fastest and 16.6 times faster than patched-jsdom. jsdom is 1.1 times faster than patched-jsdom.

querySelector()

Selector	jsdom v25.0.0 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: querySelector('.content')	30,752 ops/sec ±1.40%	3,402,064 ops/sec ±1.11%	10,466 ops/sec ±0.91%	30,353 ops/sec ±1.46%	happydom is the fastest and 112.1 times faster than patched-jsdom. jsdom is 1.0 times faster than patched-jsdom.
compound selector: querySelector('p.content[id]:is(:last-child, :only-child)')	9,716 ops/sec ±1.63%	3,318,668 ops/sec ±1.19%	9,481 ops/sec ±0.59%	9,123 ops/sec ±0.47%	happydom is the fastest and 363.8 times faster than patched-jsdom. jsdom is 1.1 times faster than patched-jsdom.
complex selector: querySelector('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	219 ops/sec ±1.75%	F	1,270 ops/sec ±0.34%	779 ops/sec ±2.08%	linkedom is the fastest and 1.6 times faster than patched-jsdom. patched-jsdom is 3.6 times faster than jsdom.
complex selector: querySelector('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner:has(> .content)')	F	F	1,532 ops/sec ±1.81%	516 ops/sec ±1.93%	linkedom is the fastest and 3.0 times faster than patched-jsdom.
complex selector within logical pseudo-class: querySelector(':is(.box > .content, .block > .content)')	3,215 ops/sec ±0.60%	F	9,656 ops/sec ±1.10%	159,781 ops/sec ±2.23%	patched-jsdom is the fastest. patched-jsdom is 49.7 times faster than jsdom.

querySelectorAll()

Selector	jsdom v25.0.0 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: querySelectorAll('.content')	3,145 ops/sec ±1.24%	7,471,952 ops/sec ±0.97%	1,187 ops/sec ±0.18%	3,330 ops/sec ±0.40%	happydom is the fastest and 2244.1 times faster than patched-jsdom. patched-jsdom is 1.1 times faster than jsdom.
compound selector: querySelectorAll('p.content[id]:is(:last-child, :only-child)')	969 ops/sec ±1.23%	6,444,347 ops/sec ±0.86%	1,155 ops/sec ±1.22%	993 ops/sec ±0.21%	happydom is the fastest and 6486.9 times faster than patched-jsdom. patched-jsdom is 1.0 times faster than jsdom.
complex selector: querySelectorAll('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	221 ops/sec ±1.66%	F	418 ops/sec ±1.84%	905 ops/sec ±1.45%	patched-jsdom is the fastest. patched-jsdom is 4.1 times faster than jsdom.
complex selector: querySelectorAll('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner:has(> .content)')	F	F	454 ops/sec ±0.15%	567 ops/sec ±1.60%	patched-jsdom is the fastest.
complex selector within logical pseudo-class: querySelectorAll(':is(.box > .content, .block > .content)')	295 ops/sec ±1.89%	F	515 ops/sec ±1.81%	790 ops/sec ±1.60%	patched-jsdom is the fastest. patched-jsdom is 2.7 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)