WPT
wpt / custom-elements / attribute-changed-callback.html
Spec: https://html.spec.whatwg.org/multipage/custom-elements.html ↗
Runs: Chrome 155.0.8041.0 (wpt@4a01b83e3, 2026-09-04) | Firefox 157.0a1 (wpt@4a01b83e3, 2026-09-04) | Safari 251 preview (wpt@a1e944e7a, 2026-09-04) | Ladybird 1.0-a7825 (wpt@4a01b83e3, 2026-09-04) | Servo Servo 0.6 (wpt@7e3d005d7, 2026-09-03) | Blitz a50cb8971 (wpt@a95401e4e, 2026-09-03)
View on the Blitz WPT dashboard | Open test on wpt.live | wpt.fyi
| Chrome | Firefox | Safari | Ladybird | Servo | Blitz | |
|---|---|---|---|---|---|---|
| Total | 13/13 | 13/13 | 13/13 | 13/13 | 13/13 | NOT RUN |
| Subtest | Chrome | Firefox | Safari | Ladybird | Servo | Blitz |
|---|---|---|---|---|---|---|
| setAttribute and removeAttribute must enqueue and invoke attributeChangedCallback | PASS | PASS | PASS | PASS | PASS | — |
| setAttributeNS and removeAttributeNS must enqueue and invoke attributeChangedCallback | PASS | PASS | PASS | PASS | PASS | — |
| setAttributeNode and removeAttributeNode must enqueue and invoke attributeChangedCallback for an HTML attribute | PASS | PASS | PASS | PASS | PASS | — |
| setAttributeNode and removeAttributeNS must enqueue and invoke attributeChangedCallback for an SVG attribute | PASS | PASS | PASS | PASS | PASS | — |
| toggleAttribute must enqueue and invoke attributeChangedCallback | PASS | PASS | PASS | PASS | PASS | — |
| Mutating attributeChangedCallback after calling customElements.define must not affect the callback being invoked | PASS | PASS | PASS | PASS | PASS | — |
| attributedChangedCallback must not be invoked when the observed attributes does not contain the attribute | PASS | PASS | PASS | PASS | PASS | — |
| Mutating observedAttributes after calling customElements.define must not affect the set of attributes for which attributedChangedCallback is invoked | PASS | PASS | PASS | PASS | PASS | — |
| attributedChangedCallback must be enqueued for attributes specified in a non-Array iterable observedAttributes | PASS | PASS | PASS | PASS | PASS | — |
| attributedChangedCallback must be enqueued for style attribute change by mutating inline style declaration | PASS | PASS | PASS | PASS | PASS | — |
| attributedChangedCallback must not be enqueued when mutating inline style declaration if the style attribute is not observed | PASS | PASS | PASS | PASS | PASS | — |
| Upgrading a parser created element must enqueue and invoke attributeChangedCallback for an HTML attribute | PASS | PASS | PASS | PASS | PASS | — |
| Upgrading a cloned element must enqueue and invoke attributeChangedCallback for an HTML attribute | PASS | PASS | PASS | PASS | PASS | — |