@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

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);
    };
  }
});

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)	✓
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:popover-open	✓
E:state(v)	✓	*1
:host	✓
:host(s)	✓
:host‑context(s)	✓
:host(:state(v))	✓	*1
:host:has(rs1, rs2, ...)	✓
:host(s):has(rs1, rs2, ...)	✓
:host‑context(s):has(rs1, rs2, ...)	✓

*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;
  }
}

Performance

See benchmark for the latest results.

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

matches()

Selector	jsdom v25.0.1 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: matches('.content')	117,468 ops/sec ±4.45%	349,037 ops/sec ±2.71%	7,986 ops/sec ±0.83%	121,277 ops/sec ±0.58%	happydom is the fastest and 2.9 times faster than patched-jsdom. patched-jsdom is 1.0 times faster than jsdom.
compound selector: matches('p.content[id]:is(:last-child, :only-child)')	109,103 ops/sec ±1.81%	323,742 ops/sec ±16.05%	7,826 ops/sec ±0.70%	89,905 ops/sec ±0.25%	happydom is the fastest and 3.6 times faster than patched-jsdom. jsdom is 1.2 times faster than patched-jsdom.
compound selector: matches('p.content[id]:is(:invalid-nth-child, :only-child)')	F	350,215 ops/sec ±2.68%	F	44,510 ops/sec ±0.33%	happydom is the fastest and 7.9 times faster than patched-jsdom.
compound selector: matches('p.content[id]:not(:is(.foo, .bar))')	106,858 ops/sec ±0.43%	352,297 ops/sec ±0.17%	7,639 ops/sec ±0.61%	87,013 ops/sec ±0.63%	happydom is the fastest and 4.0 times faster than patched-jsdom. jsdom is 1.2 times faster than patched-jsdom.
complex selector: matches('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	70,868 ops/sec ±0.57%	F	4,876 ops/sec ±0.49%	64,719 ops/sec ±0.36%	jsdom is the fastest and 1.1 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	4,752 ops/sec ±0.54%	15,398 ops/sec ±3.41%	patched-jsdom is the fastest.
complex selector within logical pseudo-class: matches(':is(.box > .content, .block > .content)')	99,626 ops/sec ±0.63%	F	5,129 ops/sec ±0.45%	95,577 ops/sec ±0.65%	jsdom is the fastest and 1.0 times faster than patched-jsdom.
nested and chained :not() selector: matches('p:not(:is(:not(.content))):not(.foo)')	F	F	4,701 ops/sec ±13.49%	82,153 ops/sec ±0.68%	patched-jsdom is the fastest.

closest()

Selector	jsdom v25.0.1 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: closest('.container')	93,212 ops/sec ±0.46%	263,009 ops/sec ±30.00%	7,996 ops/sec ±0.64%	91,205 ops/sec ±0.35%	happydom is the fastest and 2.9 times faster than patched-jsdom. jsdom is 1.0 times faster than patched-jsdom.
compound selector: closest('div.container[id]:not(.foo, .box)')	64,257 ops/sec ±0.27%	F	7,412 ops/sec ±0.84%	55,072 ops/sec ±0.33%	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 > .content')	65,291 ops/sec ±0.22%	F	4,890 ops/sec ±0.41%	58,028 ops/sec ±0.64%	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:has(> .content)')	F	F	4,703 ops/sec ±1.06%	13,256 ops/sec ±0.48%	patched-jsdom is the fastest.
complex selector within logical pseudo-class: closest(':is(.container > .content, .container > .box)')	75,927 ops/sec ±0.36%	307,805 ops/sec ±0.48%	5,108 ops/sec ±0.41%	69,864 ops/sec ±0.18%	happydom is the fastest and 4.4 times faster than patched-jsdom. jsdom is 1.1 times faster than patched-jsdom.
nested and chained :not() selector: closest('div:not(:is(:not(.container))):not(.box)')	F	F	7,399 ops/sec ±0.61%	70,308 ops/sec ±0.48%	patched-jsdom is the fastest.

querySelector()

Selector	jsdom v25.0.1 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: querySelector('.content')	22,886 ops/sec ±0.82%	193,155 ops/sec ±54.70%	9,439 ops/sec ±0.63%	78,132 ops/sec ±0.17%	happydom is the fastest and 2.5 times faster than patched-jsdom. patched-jsdom is 3.4 times faster than jsdom.
compound selector: querySelector('p.content[id]:is(:last-child, :only-child)')	8,542 ops/sec ±0.62%	336,066 ops/sec ±0.67%	9,046 ops/sec ±0.77%	35,397 ops/sec ±1.69%	happydom is the fastest and 9.5 times faster than patched-jsdom. patched-jsdom is 4.1 times faster than jsdom.
complex selector: querySelector('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner > .content')	204 ops/sec ±0.44%	F	1,186 ops/sec ±0.50%	626 ops/sec ±0.57%	linkedom is the fastest and 1.9 times faster than patched-jsdom. patched-jsdom is 3.1 times faster than jsdom.
complex selector: querySelector('.box:first-child ~ .box:nth-of-type(4n+1) + .box[id] .block.inner:has(> .content)')	F	F	1,476 ops/sec ±0.74%	453 ops/sec ±0.78%	linkedom is the fastest and 3.3 times faster than patched-jsdom.
complex selector within logical pseudo-class: querySelector(':is(.box > .content, .block > .content)')	3,144 ops/sec ±0.45%	F	8,766 ops/sec ±0.78%	77,257 ops/sec ±0.50%	patched-jsdom is the fastest. patched-jsdom is 24.6 times faster than jsdom.
nested and chained :not() selector: querySelector('p:not(:is(:not(.content))):not(.foo)')	F	F	8,972 ops/sec ±0.70%	70,248 ops/sec ±0.39%	patched-jsdom is the fastest.

querySelectorAll()

Selector	jsdom v25.0.1 (nwsapi)	happy-dom	linkeDom	patched-jsdom (dom-selector)	Result
simple selector: querySelectorAll('.content')	1,292 ops/sec ±0.58%	494 ops/sec ±44.77%	1,091 ops/sec ±0.72%	1,226 ops/sec ±0.45%	jsdom is the fastest and 1.1 times faster than patched-jsdom.
compound selector: querySelectorAll('p.content[id]:is(:last-child, :only-child)')	688 ops/sec ±0.91%	455 ops/sec ±42.98%	1,096 ops/sec ±0.90%	656 ops/sec ±0.50%	linkedom is the fastest and 1.7 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')	206 ops/sec ±0.58%	F	393 ops/sec ±0.62%	209 ops/sec ±0.58%	linkedom is the fastest and 1.9 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:has(> .content)')	F	F	421 ops/sec ±0.83%	186 ops/sec ±0.49%	linkedom is the fastest and 2.3 times faster than patched-jsdom.
complex selector within logical pseudo-class: querySelectorAll(':is(.box > .content, .block > .content)')	288 ops/sec ±0.64%	F	471 ops/sec ±0.71%	796 ops/sec ±2.11%	patched-jsdom is the fastest. patched-jsdom is 2.8 times faster than jsdom.
nested and chained :not() selector: querySelectorAll('p:not(:is(:not(.content))):not(.foo)')	F	F	1,108 ops/sec ±0.45%	1,316 ops/sec ±0.48%	patched-jsdom is the fastest.

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)