solidjs / solid / 36589644536

74%

main: 89%

push

github

Stage 7: attribute slots, second form — one slot per data context, bound per position (#3704)

Retires the first form (one slot per element, its return spread onto that element) and Stage 6's `_bnd` behavior claims in favor of §9.2.3's second form: a slot call returns a proxy whose reads yield `SLOT_VALUE` stand-ins, every server attribute helper recognizes the brand and emits an `_s:<position>="<occurrence>:<key>"` marker beside the t=0 value (document face) or beside nothing (stream face), and the client binds one memo and one render effect per occurrence, writing positions by marker.

- Both compilers, under `serverComponents`, route dynamic `class`/`style` through a whole-attribute hole and pass spread-element `ref`/`on*` claims to `ssrElement` (new optional seventh `claims` argument); plain SSR output is unchanged.
- Spread-element handler positions settle in source order and by key presence, matching the client's `spread`/`merge()`: a later source's key, `undefined` included, owns the position; duplicate named handlers keep the last; refs merge.
- An occurrence detaches its listeners on dispose; released positions keep server-owned values; stand-ins passed as slot args are scrubbed (plain objects and arrays) with an `arg` finding.
- The document-face border walk is cycle-safe with side effects run once, and keeps an acyclic fast path.
- `$key` on spread intrinsics (native compiler); `dynamic`'s address signal is `ownedWrite`; a showing call's refetch resolves after apply.

Size-Exception: frames eager client +927 B, page base +896 B, page live +807 B (frozen caps raised per the ledger); client apps −10..−77 B.

Co-authored-by: Claude via Cursor <noreply@cursor.com>

625 of 912 branches covered (68.53%)

Branch coverage included in aggregate %.

920 of 1181 relevant lines covered (77.9%)

27.42 hits per line