Issues

• Script and style elements are not closed when their text ends with < followed by non-space characters

  capricorn86/happy-dom#2458 · Filter by author gildas-lormeau opened on Oct 4, 2026

• fetch: an abort right after fetch() is lost, and a cancelled body throws "Controller is already closed"

  capricorn86/happy-dom#2456 · Filter by author Stanzilla opened on Oct 4, 2026

• NodeUtility.isFollowing is O(document size), making Range operations quadratic on large documents

  capricorn86/happy-dom#2454 · Filter by author janosh opened on Oct 3, 2026

• Incorrect nodeName property for DocumentFragment instance

  bug
  capricorn86/happy-dom#2451 · Filter by author vsn4ik opened on Sep 29, 2026

• Inside a <template>, <table><tr> never gets the implied <tbody> — the permitted-parent correction is guarded off wholesale

  capricorn86/happy-dom#2450 · Filter by author cerbris opened on Sep 28, 2026
  1

• HTMLInputElement type=time only shows minutes if zero seconds supplied

  bug
  capricorn86/happy-dom#2448 · Filter by author imirkin opened on Sep 28, 2026
  1

• Typescript: error TS2694: Namespace '"node:stream/web"' has no exported member 'UnderlyingDefaultSource'.

  bug
  capricorn86/happy-dom#2446 · Filter by author Jme797 opened on Sep 25, 2026

• ES module compiler doesn't rewrite import.meta after ?, which breaks every code-split Vite bundle

  bug
  capricorn86/happy-dom#2445 · Filter by author Marvin-Brouwer opened on Sep 25, 2026

• :empty styles are applied to elements that only contain text

  bug
  capricorn86/happy-dom#2443 · Filter by author samwato-ax opened on Sep 25, 2026

• HTMLOutputElement.defaultValue is "" instead of the text content, so form.reset() clears <output>

  capricorn86/happy-dom#2441 · Filter by author ubugeeei opened on Sep 23, 2026
  1

• requestSubmit() without a button sets SubmitEvent.submitter to the form, which breaks FormData (and React 19.3 form actions)

  bug
  capricorn86/happy-dom#2438 · Filter by author jonathanpalma opened on Sep 21, 2026

• Missing CSSRuleList::item function

  bug
  capricorn86/happy-dom#2436 · Filter by author soullivaneuh opened on Sep 21, 2026

• Missing StyleSheetList::item function

  bug
  capricorn86/happy-dom#2435 · Filter by author soullivaneuh opened on Sep 21, 2026

• TypeError: Illegal constructor on some CSS constuctors

  bug
  capricorn86/happy-dom#2434 · Filter by author soullivaneuh opened on Sep 21, 2026
  2

• @happy-dom/jest-environment leaks the Window on teardown: window.close() is a no-op for the top-level window

  bug
  capricorn86/happy-dom#2424 · Filter by author Serg-develop opened on Sep 18, 2026

• Hangs indefinitely in isInclusiveAncestor when an element defines its own host property

  bug
  capricorn86/happy-dom#2420 · Filter by author sbays opened on Sep 16, 2026

• getComputedStyle() flattens ancestor custom properties, turning a legal cross-element var() chain into a false cycle

  capricorn86/happy-dom#2419 · Filter by author dimitribee opened on Sep 14, 2026

• FormData.set() doesn't remove duplicate entries with the same name

  capricorn86/happy-dom#2416 · Filter by author marciomazza opened on Sep 13, 2026

• FormData only adds one entry for a <select multiple> with several selected options

  capricorn86/happy-dom#2414 · Filter by author marciomazza opened on Sep 13, 2026

• Animation.cancel() rejects the finished promise without marking it handled, surfacing an unhandled rejection in Node

  capricorn86/happy-dom#2412 · Filter by author ezwep opened on Sep 11, 2026

• [hidden] elements are not display: none in getComputedStyle()

  bug
  capricorn86/happy-dom#2411 · Filter by author zhemaituk opened on Sep 10, 2026

• CSSStyleDeclaration discards -webkit-line-clamp and its JavaScript aliases

  capricorn86/happy-dom#2404 · Filter by author jesusgalhub opened on Sep 10, 2026

• Element.animate() finished effects are not reflected in computed styles and bypass fake timers

  capricorn86/happy-dom#2403 · Filter by author jesusgalhub opened on Sep 10, 2026

• Regression in 20.12.1: -webkit-text-fill-color is missing from getComputedStyle, even set to a literal

  capricorn86/happy-dom#2401 · Filter by author ogysha opened on Sep 9, 2026

• Regression in 20.13.1: color: inherit is ignored when an earlier declaration set a value (incomplete fix for #2347)

  capricorn86/happy-dom#2400 · Filter by author ogysha opened on Sep 9, 2026