Files

giles 4df4de7f79 host: doc — SPA WASM bundle rebuild attempt failed (Char.chr crash), reverted

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2026-06-28 21:00:25 +00:00

4.7 KiB

Raw Blame History

Host blog → SPA via the SX-htmx engine (WASM OCaml kernel)

Turn the blog (lib/host/blog.sx) into a single-page app using the in-repo SX hypermedia engine (web/engine.sx — "our htmx"): boot the WASM OCaml kernel (the same evaluator the server runs) in the browser, and sx-boost every link/form into a fragment swap into #content — no full reloads, history kept, graceful degradation to plain server-rendered pages with no JS.

Status

DONE — server side (verified, all green):

lib/host/static.sx — GET /static/** serves files under shared/static via the file-read primitive (content-type by extension, path-traversal guarded, 404 on missing). Mounted in serve.sh + the route list. Tested: kernel JS 200 + correct ctype + exact bytes; .wasm binary-exact with application/wasm; traversal/missing → 404.
lib/host/blog.sx host/blog--page is now the SPA shell: full page = WASM boot scripts (/static/wasm/sx_browser.bc.wasm.js + sx-platform.js) + a sx-boost="#content" wrapper div + #content. On the SX-Request: true header (a boosted nav) it returns ONLY the inner content (fragment) so the engine swaps it into #content. All 13 page handlers thread req. Tested: full page carries scripts+boost+#content; SX-Request returns the bare fragment.
docker-compose.dev-sx-host.yml mounts ./shared/static so the live container can serve the kernel.
lib/host/playwright/spa-check.spec.js + run-spa-check.sh — browser check (boot, boost, fragment swap, back button).

DONE — client side, partial:

The WASM kernel BOOTS in a headless browser: globalThis.SxKernel is an object, <html data-sx-ready="true"> is set, the web-stack modules load.
Fixed: this worktree's shared/static/wasm/sx_browser.bc.wasm.assets/ was missing 5 of 11 .wasm units (sx-, unix-, re-, start-, dune__exe__Sx_browser-); copied the complete set from the main worktree.

BLOCKER — boost does not activate (boosted links: 0 / N):

The bundled .sxbc bytecode throws VM: unknown opcode 0 against this worktree's sx_browser.bc.wasm.js kernel, so sx-platform.js falls back to .sx source for every web-stack module. Source fallback works for all modules EXCEPT boot.sx, which then fails with Expected list, got string — so the boot sequence that wires process-elements → process-boosted doesn't complete and no link gets _sxBoundboost.
Root cause: the .sxbc in shared/static/wasm/sx/ are out of sync with the WASM kernel (sx.rose-ash.com avoids this because its Docker image ships a consistent bundle and it navigates via client-router page-routes, not boost).

Rebuild attempt (2026-06-28) — FAILED, reverted

Tried it: dune build browser/sx_browser.bc.wasm.js succeeded (with many integer-overflow warnings — "generated code might be incorrect"), and node hosts/ocaml/browser/compile-modules.js shared/static/wasm recompiled all 35 .sxbc cleanly. But the freshly-built kernel crashes on init in the browser: Fatal error: exception Invalid_argument("Char.chr") — so SxKernel never initialises (worse than before). The integer-overflow truncation during wasm codegen is the likely culprit (a SHA/char constant). Reverted shared/static/wasm/ to the main-worktree bundle (which boots cleanly — verified SxKernel + data-sx-ready). So a naive in-worktree rebuild is NOT the fix; the wasm build itself needs investigating (wasm_of_ocaml version? the merged sx-vm-extensions/resolver changes interacting with codegen?).

Next step — rebuild a consistent WASM bundle

scripts/sx-build-all.sh does: build the browser wasm target → sync web .sx into hosts/ocaml/browser/dist/sx/ → node hosts/ocaml/browser/compile-modules.js (recompiles .sxbc via the native sx_server binary) → copy into shared/static/wasm/. The browser wasm target is NOT built in this worktree (hosts/ocaml/_build/default/browser/ is empty), so this needs the wasm_of_ocaml toolchain set up first. Once the .sxbc match the kernel, the bytecode path loads (no source fallback), boot.sx runs, and process-boosted binds the links — then the SPA Playwright check should pass.

Alternatively: build the browser kernel in the main worktree (which has the pipeline) and copy a consistent sx_browser.bc.wasm.js + assets + .sxbc set into this worktree's shared/static/wasm/.

Deploy note

The live container is NOT redeployed with the SPA shell yet — it keeps running the pre-SPA blog.sx in memory (the native host doesn't hot-reload). Don't recreate the container until the bundle is consistent and the SPA Playwright check is green, to avoid shipping a kernel that boots but doesn't boost. (Even if it is recreated, pages degrade gracefully: links still do normal full-page nav.)

4.7 KiB Raw Blame History