jsdom

• Overhauled resource loading customization. See the new README for details on the new API.
• Added MIME type sniffing to <iframe> and <frame> loads.
• Regression: WebSockets are no longer correctly throttled to one connection per origin. This is a result of the bug at [nodejs/und...

• Added TextEncoder and TextDecoder.
• Improved decoding of HTML bytes by using the new @exodus/bytes package; it is now much more correct. (ChALkeR)
• Improved decoding of XML bytes to use UTF-8 more often, instead of sniffing for <meta charset> or using the parent frame's encoding.
• Fixed a memory leak when Ranges were used and then th...

• Improved CSS parsing and CSSOM object APIs via updates to @acemir/cssom. (acemir)

• Added CSSGroupingRule, CSSNestedDeclarations, CSSConditionRule, CSSContainerRule, CSSScopeRule, CSSSupportsRule, CSSLayerBlockRule, and CSSLayerStatementRule to jsdom Windows. (acemir)
• Improved CSS parsing and CSSOM object APIs via updates to @acemir/cssom. (acemir)
• Fixed @import-ed stylesheets to be properly exposed to C...

• Improved CSS parsing by switching to @acemir/cssom, including support for nested selectors, nested declarations, layer statements, and improved at-rule validation. (acemir)
• Fixed some selector cache invalidation issues where changes to attributes were not being picked up. (asamuzaK)
• Fixed package.json "engines" field to reflect the new m...

This release inadvertently raised the minimum Node.js version from v20.0.0 to v20.19.0+, v22.12.0+, v24.0.0+. (This happened via a dependency update.) This probably should have been a breaking (major) change, instead of happening in a patch version, since it prevents using earlier Node.js versions.

After further testing, we found that most of our development dependencies also require these...

Changes since 26.1.0

• Node.js v20 is now the minimum supported version.
• Added a variety of event constructors, even though we do not implement their associated specifications or ever fire them: BeforeUnloadEvent, BlobEvent, DeviceMotionEvent (omitting requestPermission()), DeviceOrientationEvent (omitting requestPermission()), PointerEvent, PromiseRejectionEvent, and `Tr...

• Breaking change: upgraded tough-cookie, which now considers URLs like http://localhost/ to be secure contexts (per the spec), and thus will return Secure-flagged cookies for such URLs. (colincasey)
• Added customElements.getName(). (mash-graz)
• Changed the <input> element's pattern="" attribute to use the `v...

Significantly improved specification conformance for the Window object, including named properties and changing various data properties to accessor properties. This is not likely to be breaking, but since it's a complex change to such a core object, we're happy to do another beta testing release with this included before graduating the v27 line to stable.

Additionally, updated [cssstyle](ht...

Breaking changes:

• Node.js v20+ is now the minimum supported version.
• The user agent stylesheet is now derived from the HTML Standard, instead of from Chromium. This might change the results you see from getComputedStyle().
• The virtual console has seen a number of changes:
  • `"...