Sourced from jsdom's releases.

Version 16.5.3

• Fixed infinite recursion when using MutationObservers to observe elements inside a MutationObserver callback.

Version 16.5.2

• Fixed Access-Control-Allow-Headers: * to work with XMLHttpRequest. (silviot)
• Fixed xhr.response to strip any leading BOM when xhr.responseType is "json".
• Fixed new Text() and new Comment() constructors to properly set the resulting node's ownerDocument.
• Fixed customElements.whenDefined() to resolve its returned promise with the custom element constructor, per recent spec updates. (ExE-Boss)
• Fixed parsing to ensure that <svg>\<template></template></svg> does not throw an exception, but instead correctly produces a SVG-namespace \<template> element.
• Fixed domParser.parseFromString() to treat <noscript> elements appropriately.
• Fixed form control validity checking when the control was outside the <form> element and instead associated using the form="" attribute.
• Fixed legendEl.form to return the correct result based on its parent <fieldset>.
• Fixed optionEl.text to exclude <script> descendants.
• Fixed radio buttons and checkboxes to not fire input and change events when disconnected.
• Fixed inputEl.indeterminate to reset to its previous value when canceling a click event on a checkbox or radio button.
• Fixed the behavior of event handler attributes (e.g. onclick="...code...") when there were global variables named element or formOwner. (ExE-Boss)
• On Node.js v14.6.0+ where WeakRefs are available, fixed NodeIterator to no longer stop working when more than ten NodeIterator instances are created, and to use less memory due to inactive NodeIterators sticking around. (ExE-Boss)

Version 16.5.1

• Fixed a regression that broke customElements.get() in v16.5.0. (fdesforges)
• Fixed window.event to have a setter which overwrites the window.event property with the given value, per the specification. This fixes an issue where after upgrading to jsdom v16.5.0 you would no longer be able to set a global variable named event in the jsdom context.

Version 16.5.0

• Added window.queueMicrotask().
• Added window.event.
• Added inputEvent.inputType. (diegohaz)
• Removed ondragexit from Window and friends, per a spec update.
• Fixed the URL of about:blank iframes. Previously it was getting set to the parent's URL. (SimonMueller)
• Fixed the loading of subresources from the filesystem when they had non-ASCII filenames.
• Fixed the hidden="" attribute to cause display: none per the user-agent stylesheet. (ph-fritsche)
• Fixed the new File() constructor to no longer convert / to :, per a pending spec update.
• Fixed mutation observer callbacks to be called with the MutationObserver instance as their this value.
• Fixed <input type=checkbox> and <input type=radio> to be mutable even when disabled, per a spec update.
• Fixed XMLHttpRequest to not fire a redundant final progress event if a progress event was previously fired with the same loaded value. This would usually occur with small files.
• Fixed XMLHttpRequest to expose the Content-Length header on cross-origin responses.
• Fixed xhr.response to return null for failures that occur during the middle of the download.
• Fixed edge cases around passing callback functions or event handlers. (ExE-Boss)
• Fixed edge cases around the properties of proxy-like objects such as localStorage or dataset. (ExE-Boss)
• Fixed a potential memory leak with custom elements (although we could not figure out how to trigger it). (soncodi)

Version 16.4.0

• Added a not-implemented warning if you try to use the second pseudo-element argument to getComputedStyle(), unless you pass a ::part or ::slotted pseudo-element, in which case we throw an error per the spec. (ExE-Boss)
• Improved the performance of repeated access to el.tagName, which also indirectly improves performance of selector matching and style computation. (eps1lon)
• Fixed form.elements to respect the form="" attribute, so that it can contain non-descendant form controls. (ccwebdesign)
• Fixed el.focus() to do nothing on disconnected elements. (eps1lon)
• Fixed el.focus() to work on SVG elements. (zjffun)
• Fixed removing the currently-focused element to move focus to the <body> element. (eps1lon)
• Fixed imgEl.complete to return true for <img> elements with empty or unset src="" attributes. (strager)
• Fixed imgEl.complete to return true if an error occurs loading the <img>, when canvas is enabled. (strager)
• Fixed imgEl.complete to return false if the <img> element's src="" attribute is reset. (strager)

... (truncated)

Sourced from jsdom's changelog.

16.5.3

• Fixed infinite recursion when using MutationObservers to observe elements inside a MutationObserver callback.

16.5.2

• Fixed Access-Control-Allow-Headers: * to work with XMLHttpRequest. (silviot)
• Fixed xhr.response to strip any leading BOM when xhr.responseType is "json".
• Fixed new Text() and new Comment() constructors to properly set the resulting node's ownerDocument.
• Fixed customElements.whenDefined() to resolve its returned promise with the custom element constructor, per recent spec updates. (ExE-Boss)
• Fixed parsing to ensure that <svg>\<template></template></svg> does not throw an exception, but instead correctly produces a SVG-namespace \<template> element.
• Fixed domParser.parseFromString() to treat <noscript> elements appropriately.
• Fixed form control validity checking when the control was outside the <form> element and instead associated using the form="" attribute.
• Fixed legendEl.form to return the correct result based on its parent <fieldset>.
• Fixed optionEl.text to exclude <script> descendants.
• Fixed radio buttons and checkboxes to not fire input and change events when disconnected.
• Fixed inputEl.indeterminate to reset to its previous value when canceling a click event on a checkbox or radio button.
• Fixed the behavior of event handler attributes (e.g. onclick="...code...") when there were global variables named element or formOwner. (ExE-Boss)
• On Node.js v14.6.0+ where WeakRefs are available, fixed NodeIterator to no longer stop working when more than ten NodeIterator instances are created, and to use less memory due to inactive NodeIterators sticking around. (ExE-Boss)

16.5.1

• Fixed a regression that broke customElements.get() in v16.5.0. (fdesforges)
• Fixed window.event to have a setter which overwrites the window.event property with the given value, per the specification. This fixes an issue where after upgrading to jsdom v16.5.0 you would no longer be able to set a global variable named event in the jsdom context.

16.5.0

• Added window.queueMicrotask().
• Added window.event.
• Added inputEvent.inputType. (diegohaz)
• Removed ondragexit from Window and friends, per a spec update.
• Fixed the URL of about:blank iframes. Previously it was getting set to the parent's URL. (SimonMueller)
• Fixed the loading of subresources from the filesystem when they had non-ASCII filenames.
• Fixed the hidden="" attribute to cause display: none per the user-agent stylesheet. (ph-fritsche)
• Fixed the new File() constructor to no longer convert / to :, per a pending spec update.
• Fixed mutation observer callbacks to be called with the MutationObserver instance as their this value.
• Fixed <input type=checkbox> and <input type=radio> to be mutable even when disabled, per a spec update.
• Fixed XMLHttpRequest to not fire a redundant final progress event if a progress event was previously fired with the same loaded value. This would usually occur with small files.
• Fixed XMLHttpRequest to expose the Content-Length header on cross-origin responses.
• Fixed xhr.response to return null for failures that occur during the middle of the download.
• Fixed edge cases around passing callback functions or event handlers. (ExE-Boss)
• Fixed edge cases around the properties of proxy-like objects such as localStorage or dataset. (ExE-Boss)
• Fixed a potential memory leak with custom elements (although we could not figure out how to trigger it). (soncodi)

16.4.0

• Added a not-implemented warning if you try to use the second pseudo-element argument to getComputedStyle(), unless you pass a ::part or ::slotted pseudo-element, in which case we throw an error per the spec. (ExE-Boss)
• Improved the performance of repeated access to el.tagName, which also indirectly improves performance of selector matching and style computation. (eps1lon)
• Fixed form.elements to respect the form="" attribute, so that it can contain non-descendant form controls. (ccwebdesign)
• Fixed el.focus() to do nothing on disconnected elements. (eps1lon)

... (truncated)

• e4c4004 Version 16.5.3
• 2f41466 Fix MutationObserver infinite loop bugs (#3173)
• b232f2a Run partially-failing WPTs in the custom-elements directory
• 35e103e Run partially-failing WPTs in the cors directory
• 77b660a Run partially-failing WPTs in the FileAPI directory
• d8a245f Use InnerHTML mixin for innerHTML definition (#2981)
• bd50bbe Version 16.5.2
• d5cfd69 Fix event handler ObjectEnvironment instantiation
• 93e3d4a Remove vestigial concurrentNodeIterators option-passing
• c92f9c1 Check all associated elements for form validity
• Additional commits viewable in compare view

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
• @dependabot use these labels will set the current labels as the default for future PRs for this repo and language
• @dependabot use these reviewers will set the current reviewers as the default for future PRs for this repo and language
• @dependabot use these assignees will set the current assignees as the default for future PRs for this repo and language
• @dependabot use this milestone will set the current milestone as the default for future PRs for this repo and language
• @dependabot badge me will comment on this PR with code to add a "Dependabot enabled" badge to your readme

Additionally, you can set the following in your Dependabot dashboard:

• Update frequency (including time of day and day of week)
• Pull request limits (per update run and/or open at any time)
• Out-of-range updates (receive only lockfile updates, if desired)
• Security updates (receive only security updates, if desired)