solidjs / solid / 34863695100

71%

main: 89%

push

github

fix(solid): SSR boundaries resolve children in a scope mirroring the client's flatten computed (#3414) (#3428)

* fix(solid): resolve SSR boundary children in a scope mirroring the client's flatten computed (#3414)

A server-rendered `<Errored>` fallback hydrated dead when the boundary's
children threw synchronously and the fallback was a zero-arg thunk
(`fallback={() => <Fallback />}`) inside an enclosing boundary. Both sides
hand the thunk back unresolved and the enclosing boundary unwraps it — the
client inside its second computed (`boundaryComputed(() => flatten(read(c)))`,
the boundary owner's child `…1`), the server inline under the boundary owner
(`ctx.resolve` right after the `fn` owner `…0`) — so the fallback's root
element took `…1` on the server and `…10` on the client, failed its claim,
and its handlers and effects never attached. Same misalignment for `Loading`
as the consumer, fragment children, and `Show`'s fallback thunk; an element
hole in between (compiled `scope()` ↔ transparent insert effect) was already
aligned.

The server `Errored` and `Loading` boundaries now resolve their children's
result in a virtual id scope mirroring that second computed — ssrScope's
technique: the owner keeps its identity (retry wraps capture it and read the
current pull's error handler off it; a real child owner snapshots a stale
handler and double-renders the fallback) and only its id counter is
rewritten for the resolve, retries continuing where the discovery pass left
it. The error record is serialized at the boundary's own id, read once,
since `owner.id` is rewritten while the error lands.

Parity-harness scenarios cover Errored/Loading/fragment consumers and the
Show producer, plus the element-hole control.

Closes #3414

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

* test(web): type the Show fallback thunk scenario as an element

`Show`'s `fallback` prop is typed as an element; the zero-arg... (continued)

519 of 790 branches covered (65.7%)

Branch coverage included in aggregate %.

772 of 1007 relevant lines covered (76.66%)

15.02 hits per line