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:openE:closed|Partially supported|Matching with <select>, e.g. select:open, is not supported.| |E:enabledE:disabled|✓| | |E:read‑writeE:read‑only|✓| | |E:placeholder‑shown|✓| | |E:default|✓| | |E:checked|✓| | |E:indeterminate|✓| | |E:validE:invalid|✓| | |E:requiredE:optional|✓| | |E:blank|Unsupported| | |E:user‑validE: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

Copyright (c) 2023 asamuzaK (Kazz)