WPT
wpt / html / semantics / sections / headingoffset-mutations.html
Spec: HTML ↗
Runs: Chrome 155.0.8043.0 (wpt@bffb67c05, 2026-09-05) | Firefox 157.0a1 (wpt@9b965429d, 2026-09-05) | Safari 251 preview (wpt@c29bd2aee, 2026-09-05) | Ladybird 1.0-4912a (wpt@b09f5cdca, 2026-09-05) | Servo Servo 0.6 (wpt@2c385f65e, 2026-09-04) | 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 | 0/39 | 0/39 | 39/39 | 39/39 | 0/39 | NOT RUN |
| Subtest | Chrome | Firefox | Safari | Ladybird | Servo | Blitz |
|---|---|---|---|---|---|---|
| headingoffset property mutations update descendant headings | FAIL | FAIL | PASS | PASS | FAIL | — |
| nested headingoffset property mutations propagate to descendants | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations update all heading types | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations propagate to deeply nested desendants | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations on shadow host update shadow DOM headings | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations on ancestors of shadow host propagate to shadow DOM | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations inside shadow DOM update correctly | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations on host (not slot) update slotted headings | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations propagate via host chain through nested shadow roots | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations respect level clamping | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations propagate via host chain across two levels of shadow DOM | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property propagates only via host chain through three nested shadow DOMs | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset property mutations update headings at multiple shadow DOM levels independently | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations update descendant headings | FAIL | FAIL | PASS | PASS | FAIL | — |
| nested headingoffset attribute mutations propagate to descendants | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations update all heading types | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations propagate to deeply nested desendants | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations on shadow host update shadow DOM headings | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations on ancestors of shadow host propagate to shadow DOM | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations inside shadow DOM update correctly | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations on host (not slot) update slotted headings | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations propagate via host chain through nested shadow roots | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations respect level clamping | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations propagate via host chain across two levels of shadow DOM | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute propagates only via host chain through three nested shadow DOMs | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingoffset attribute mutations update headings at multiple shadow DOM levels independently | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingreset mutations update descendant headings | FAIL | FAIL | PASS | PASS | FAIL | — |
| headingreset and headingoffset mutations interact correctly | FAIL | FAIL | PASS | PASS | FAIL | — |
| invalid headingoffset attribute values are handled correctly on mutation | FAIL | FAIL | PASS | PASS | FAIL | — |
| slot name attribute changes do not change slotted heading levels | FAIL | FAIL | PASS | PASS | FAIL | — |
| element slot attribute changes do not change heading levels | FAIL | FAIL | PASS | PASS | FAIL | — |
| slot element removal and addition do not change slotted heading levels | FAIL | FAIL | PASS | PASS | FAIL | — |
| default-to-named slot transitions do not change heading levels | FAIL | FAIL | PASS | PASS | FAIL | — |
| swapping slot names does not change slotted heading levels | FAIL | FAIL | PASS | PASS | FAIL | — |
| manual slot assignment does not change heading levels | FAIL | FAIL | PASS | PASS | FAIL | — |
| manual slot reassignment between slots does not change heading levels | FAIL | FAIL | PASS | PASS | FAIL | — |
| non-HTML elements (SVG) slotted with heading descendants get updated via host chain | FAIL | FAIL | PASS | PASS | FAIL | — |
| non-HTML elements (MathML) slotted with heading descendants get updated via host chain | FAIL | FAIL | PASS | PASS | FAIL | — |
| manual slot assignment of non-HTML elements does not change heading levels | FAIL | FAIL | PASS | PASS | FAIL | — |