Google Feedback on 4.4 Beta

Opening on the behalf of @h-joo from https://github.com/microsoft/TypeScript/issues/45047:

Readonly attributes in DOMPoint, DOMMatrix, DOMRect

Some properties of DOMPoint, DOMMatrix, DOMRect became readonly, and this no longer match the specification. This is because these types no longer override properties from the extended types to be read/write.

Compare(DOMPoint):

• https://github.com/microsoft/TypeScript/blob/release-4.3/lib/lib.dom.d.ts#L3979
• https://github.com/microsoft/TypeScript/blob/release-4.4/lib/lib.dom.d.ts#L3886

Compare(DOMMatrix):

• https://github.com/microsoft/TypeScript/blob/release-4.3/lib/lib.dom.d.ts#L3854
• https://github.com/microsoft/TypeScript/blob/release-4.4/lib/lib.dom.d.ts#L3783

Compare(DOMRect):

• https://github.com/microsoft/TypeScript/blob/release-4.3/lib/lib.dom.d.ts#L4026
• https://github.com/microsoft/TypeScript/blob/release-4.4/lib/lib.dom.d.ts#L3929

Removed Types

SpeechRecognition, RTCError got removed from lib.dom.d.ts. There are existing code which use this API, and it would be difficult to migrate without proper type support either from the compiler or from definitelyTyped.

• https://developer.mozilla.org/en-US/docs/Web/API/SpeechRecognitionEvent
• https://developer.mozilla.org/en-US/docs/Web/API/RTCError

Offscreen Rendering API changes

OffscreenCanvas still exists, but it’s marked as deprecated. Though it is no longer a value, i.e. code calling new OffscreenCanvas no longer works, it’s just an interface. We think this might be unintentional. Though, we would still be able to migrate via referring to the types defined in DefinitelyTyped.

• https://github.com/microsoft/TypeScript/blob/release-4.3/lib/lib.dom.d.ts#L11087
• https://github.com/microsoft/TypeScript/blob/release-4.4/lib/lib.dom.d.ts#L10832

ShadowRoot interface changes

ShadowRoot is a subtype of DocumentFragment. DocumentFragment has a getElementById which returns HTMLElement. In 4.4-beta, DocumentFragment no longer defines its own getElementById method, meaning HTMLElement.prototype.shadowRoot.getElementById returns Element, not HTMLElement. This causes hundreds of breakages of code using shadowRoot.

• https://github.com/microsoft/TypeScript/blob/release-4.3/lib/lib.dom.d.ts#L4985
• https://github.com/microsoft/TypeScript/blob/release-4.4/lib/lib.dom.d.ts#L4717

ChildNode interface changes

In 4.4, ChildNode no longer extends Node. This seems like a bug.

• https://github.com/microsoft/TypeScript/blob/release-4.3/lib/lib.dom.d.ts#L3531
• https://github.com/microsoft/TypeScript/blob/release-4.4/lib/lib.dom.d.ts#L3487

DocumentOrShadowRoot interface changes

DocumentOrShadowRoot no longer has getSelection, elementFromPoint, elementsFromPoint, caretFromRange. We also couldn’t find in the repo whether this was intentional or not.

• https://github.com/microsoft/TypeScript/blob/release-4.3/lib/lib.dom.d.ts#L4995
• https://github.com/microsoft/TypeScript/blob/release-4.4/lib/lib.dom.d.ts#L4725

[saschanaz]

Seems that elementFromPoint and elementsFromPoint should be restored since those are supported everywhere.

[h-joo]

Great, now all makes sense. Thank you for your help!!