Coverage / cssom

CSS Object Model (CSSOM)

Specification: drafts.csswg.org/cssom-1/. 16 interfaces defined here, 90 members exposed on Window (Web IDL). Group: Test DOM core.

Existence only: “present” means the name is defined where Web IDL puts it, not that it behaves as the standard says. The featured checks test behavior.

Share present per engine
Engine	Members present	Interfaces present
warpdom0.1.6maintainer's engine	93% (84 of 90)	16 of 16
happy-dom21.0.3	43% (39 of 90)	7 of 16
jsdom30.1.3	76% (68 of 90)	14 of 16
linkedom0.18.13	3% (3 of 90)	0 of 16

CSSnamespace, 1 memberPresentPresentPresentMissing

CSSGroupingRule3 membersPresentPresentPresentMissing

CSSImportRule5 membersPresentMissingPresentMissing

CSSMarginRule2 membersPresentMissingMissingMissing

CSSNamespaceRule2 membersPresentMissingPresentMissing

CSSPageDescriptors14 membersPresentMissingMissingMissing

CSSPageRule2 membersPresentMissingPresentMissing

CSSRule12 membersPresentPresentPresentMissing

CSSRuleList2 membersPresentMissingPresentMissing

CSSStyleDeclaration8 membersPresentPresentPresentMissing

CSSStyleProperties1 memberPresentMissingPresentMissing

CSSStyleRule2 membersPresentPresentPresentMissing

CSSStyleSheet9 membersPresentPresentPresentMissing

Document2 members added to Document (defined in DOM)1/22/21/20/2

HTMLElement1 member added to HTMLElement (defined in HTML)1/11/11/11/1

HTMLLinkElement1 member added to HTMLLinkElement (defined in HTML)1/11/11/10/1

HTMLStyleElement1 member added to HTMLStyleElement (defined in HTML)1/11/11/11/1

MathMLElement1 member added to MathMLElement (defined in MathML Core)0/10/10/10/1

MediaList6 membersPresentPresentPresentMissing

ProcessingInstruction1 member added to ProcessingInstruction (defined in DOM)0/10/10/10/1

ShadowRoot2 members added to ShadowRoot (defined in DOM)0/21/20/20/2

StyleSheet7 membersPresentMissingPresentMissing

StyleSheetList2 membersPresentMissingPresentMissing

SVGElement1 member added to SVGElement (defined in Scalable Vector Graphics (SVG) 1.1 (Second Edition))1/11/11/11/1

SVGStyleElement1 member added to SVGStyleElement (defined in Scalable Vector Graphics (SVG) 1.1 (Second Edition))0/11/10/10/1

Window1 member added to Window (defined in HTML)1/11/11/10/1

Probed 2026-10-19. Data: idl.json (CC BY 4.0).