`next/kernel/http_server.erl` gains `start/1(Port)` + `start/2(Port, Cfg)`. Both spawn an Erlang process that hosts
the native `http:listen/2` accept loop with the Cfg-aware `route/2` as the handler.
The blocker — the BIF wrapper in `lib/erlang/runtime.sx` had no dict↔proplist marshaling, so Erlang handler funs
couldn't pattern-match on an opaque SX request dict — is resolved by a new family of helpers added next to `er-of-sx`
(which is left untouched so non-HTTP callers see no behavioural drift):
er-request-dict-to-proplist request dict -> [{method,<<>>},{path,<<>>},...] (atom keys)
er-of-sx-deep recursive marshal: dicts -> binary-keyed proplist
er-dict-to-header-proplist headers: [{<<"content-type">>,<<"text/plain">>},...]
(binary keys keep arbitrary user input out of the atom table)
er-proplist-to-dict response proplist -> SX dict for native serialiser
er-proplist-fill! dict-set! walker over a cons-of-2-tuples
er-to-sx-deep recursive marshal: cons-of-2-tuples -> nested dict
er-proplist-2tuple? predicate distinguishing a header proplist from a binary body
`er-bif-http-listen`'s body is updated to route through the new pair instead of `er-of-sx` / `er-to-sx`. Existing
`http_listen_bif.sh` (Step 8a) still passes — the BIF's external contract (port + handler validation, registration)
hasn't changed, only the request/response shape the handler sees.
This commit also lands a small pre-existing unstaged refactor that was sitting in the same file (er-binary->string
helper above er-bif-http-listen, a "Register everything at load time." comment move, and the binary_to_list /
list_to_binary / er-iolist-walk! defines reshuffled into the er-register-builtin-bifs! body). The refactor was
agreed-out-of-scope earlier in the loop but was unblocked this iteration when the user OK'd progress on 8b-start.
Bundling it here keeps the lib/erlang/runtime.sx diff coherent.
Tests:
- `next/tests/http_marshal.sh` (10 cases) — marshaling unit tests: request dict → cons proplist; method as
<<"GET">> via SX-side proplist walker; path-as-string roundtrip; nested headers reach through binary keys;
response status/body field marshaling; nested headers reconstruct dict; full round-trip preserves status.
- `next/tests/http_server_start.sh` (6 cases) — structural verification: http_server module loaded, start bound
in module env, marshalers defined as lambdas, http:listen BIF registered. Can't invoke spawn in an Erlang test
because the cooperative scheduler (`er-sched-run-all!`) drains every runnable process before returning to the
caller, and the listener's accept loop never exits.
- `next/tests/http_server_tcp.sh` (5 cases) — **first live end-to-end transport test in the milestone**: boots
sx_server in background with FIFO-held stdin (~10s boot for all lib/erlang/*.sx loads + module compile +
Unix.bind), then drives the listener via shell-side curl over real TCP. Verifies GET / → 200, GET
/.well-known/sx-capabilities → 200, GET unknown → 404, POST /activity → 401 with no/bad bearer. Doubles as the
smoke surface for 9a-tcp / 9b-tcp.
Erlang conformance **761/761** unchanged. All standing suites stay green (http_listen_bif 5/5, log_disk 12/12,
log_rotate 10/10, term_codec 18/18).
Step 8b-start ticked in plans/fed-sx-milestone-1.md. Remaining in the milestone: 9a-tcp / 9b-tcp — partly covered
by http_server_tcp.sh's smoke probes; the full curl-driven publish flows are the next iteration.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
