writeonce/docs/examples/writeonce-framework/README.md

writeonce-framework

A web framework written in writeonce, consumed as a [deps] dependency (iteration 15). Spec: docs/superpowers/specs/2026-08-18-web-framework-design.md §B.

[deps]
writeonce-framework = { git = "https://github.com/shoneyj/writeonce-framework", rev = "v0.1.0" }

What it is

• HTTP/1.1 server core: request parsing (Content-Length bodies, %-decoded paths and query strings), response serialization, a blocking serve loop that answers 400 to malformed requests, 500 to trapping handlers (and survives), closes every fd, and honors SIGTERM. Connection policy: pipelined requests are served on one connection; idle connections close after the response — on a single-threaded server a parked keep-alive connection would block accept and starve every other client, so closing is the correct shape until fiber-per-connection serving lands (the arc — 8/11 — landed 2026-08-21; the serve-loop slice that consumes it is iteration 24's). A proxy in front simply reconnects.
• Router (router/): method + path table with :param captures into req.params; first match wins; a known path with the wrong method is 405 with the Allow header (registration order); no matching path is the framework's 404. HEAD is served free: routed as GET, body suppressed, Content-Length still names the body a GET would carry.
• Registration helpers: app.get/post/put/delete_(pattern, handler) push the route for you (delete_ because delete is the query keyword); app.add(Route { ... }) stays for anything else. A request-line Logging middleware ships in router/, and set_header(resp, name, value) is the escape hatch for headers the builders don't set.
• Handlers without closures: the language has no function values by doctrine, so a route handler is a class satisfying the Handler interface (fn handle(req: Req) -> Resp), dispatched structurally — a non-conforming handler is a compile error (WO-E205). Middleware is its own interface (fn before(req: Req) -> ?Resp; nil = continue, a Resp short-circuits).
• Auth mechanism in core (http/auth.wo): Authorization header parsing (scheme split, case-insensitive), pure-.wo base64, a constant-time comparator (ct_eq, no early exit), and the blessed principal slot — req.principal is "" until an auth middleware authenticates, then downstream handlers read who it is. BearerAuth and BasicAuth (with the WWW-Authenticate challenge) ship as middlewares; POLICY — which routes, which users, where secrets live — stays in the app, on top of bearer_token/basic_credentials/ct_eq.
• Data layer for free: handlers use @table + the query surface directly — durable, compiler-checked persistence in the same binary. No ORM, no database server.

Honest limits (v1, all deliberate)

• Single-threaded, blocking — one request at a time. Concurrency arrives underneath this same surface now that the arc (8/11) has landed (2026-08-21); the switch itself rides iteration 24's serving slice.
• TLS: none, anywhere. Deploy behind nginx/caddy; the proxy terminates TLS+ALPN and gives browsers HTTP/2 while this backend speaks HTTP/1.1 keep-alive. See the web-app sample's README for the nginx sketch.
• Content-Length bodies only (no chunked encoding), no WebSockets/SSE, JSON-first (no templates). Form-encoded bodies parse through form_values(req) (+ and %XX decoded, nil on any other content-type); multipart/form-data through multipart_parts(req) (whole-body, bounded by BODY_MAX — the arc landed 2026-08-21; streaming uploads stay parked until their own slice) with part_named for fields; media_type(req) names the body's media type for content negotiation.

The v1 surface — status ledger (2026-08-22)

The target surface of framework v1, tracked per item. The memory-rich features (TTL cache, feature flags, durable job queue, transaction { }) are framework v2 — iteration 18, spec written, NOT part of v1. Legend: ✅ shipped · 🔶 partial (gap named) · ⬜ candidate slice · ⏸ parked behind a runtime iteration · 🔧 needs a runtime/compiler seam first (pure .wo cannot express it yet).

Transport

Item	State
HTTP/1.1 parsing	🔶 parses + 400-and-survive; STRICT ambiguity rejection (duplicate/conflicting Content-Length, oversize checks beyond BODY_MAX) not audited — hardening slice
Keep-alive	✅ pipelined-serve / close-when-idle (arc landed 2026-08-21; retirement of close-when-idle rides iteration 24's fiber-per-connection slice)
Read/write/idle timeouts	🔧 net has no timeout surface — runtime seam, then a framework knob
Request size limits	✅ BODY_MAX bounds headers AND body
Unix socket binding	🔧 net.listen is TCP-only — runtime seam
Graceful SIGTERM	✅ in-flight request completes (blocking model), listener + fds closed, storage is per-commit durable (WAL fdatasync — nothing to checkpoint)

Routing

Item	State
Path matching	🔶 linear scan, first-match-wins; a radix tree is a performance slice that waits for iteration 22 to MEASURE it first
Method dispatch · path params · 404 · 405+Allow	✅
Wildcards	⬜ only :param today; *rest capture is a candidate slice
Precedence rules	🔶 registration order IS the rule (documented); specificity-based precedence unneeded until wildcards exist
Route groups	⬜ candidate slice (prefix + per-group middleware)

Request/response

Item	State
Case-insensitive headers · query parsing	✅ (names lowercased on read)
JSON · form-urlencoded · multipart	✅ all three hooks (json.decode, form_values, multipart_parts)
Content negotiation	🔶 media_type(req) covers the request side; Accept-driven response negotiation ⬜
Trusted-proxy client IP	🔶 X-Forwarded-For/-Proto parsing is expressible (candidate slice); VERIFYING the peer is the trusted proxy needs a peer-address runtime seam 🔧
Status/header setting · redirects	✅ builders + set_header
Lazy body streaming + backpressure · streaming responses · explicit commit point	⏸ UNBLOCKED by the arc (8/11 landed 2026-08-21) — stays parked until its own slice
ETag + conditional requests	⬜ candidate; wants the crypto slice's hashing

Context & middleware

Item	State
Ordered middleware chain	✅ registration order, ?Resp short-circuits
Request-scoped context	🔶 req.params + req.principal are the context today; a general req.ctx bag is a candidate slice
Guaranteed teardown	🔶 every fd closes on every path (gate-proven); no user teardown hooks yet
Cancellation into pending storage ops	⏸ UNBLOCKED by the arc (8/11 landed 2026-08-21) — stays parked until its own slice
Panic recovery	🔶 trap = 500 and the server survives ✅; "rolls back the transaction" is framework v2 (needs transaction { }, iteration 18)

Storage integration (the differentiator — framework v2 territory)

Item	State
Transaction-per-request middleware (commit on 2xx, roll back otherwise)	⏸ v2 — needs iteration 18's transaction { }
Cancellation → rollback	⏸ arc landed; still needs v2's transaction { } (iteration 18)
Migration generation + review workflow	⬜ recorded future story (script-based destructive migrations)
Eager-loading API (N+1)	⬜ query-surface work (9-series), not framework code
Tenant-scoped query roots	⬜ future; wants the query surface to grow scoped roots first

Security

Item	State
Constant-time comparison · Authorization parsing · Basic auth · principal	✅ http/auth.wo, req.principal
CORS	⬜ candidate slice (middleware + preflight answers)
Security headers	⬜ candidate slice (one middleware, a header set)
Host validation	⬜ candidate slice (middleware against a host allowlist)
Strict parsing	🔶 same item as Transport's hardening slice

Crypto (self-written, hard-stop after JWT HS256)

Item	State
base64	✅ pure .wo (http/auth.wo)
SHA-256 · SHA-512 · HMAC · CRC32	🔧 the language has NO bitwise operators — these are C runtime builtins (libc-only doctrine permits hand-rolled crypto in the runtime) or the language grows bit ops first; the fork goes to a brainstorm before the slice
Unlocks (signed cookies, CSRF, session integrity, webhook verification, JWT HS256)	⬜ framework slices AFTER the hash primitives exist; hard stop there — no RS256, no JOSE zoo

Layout and privacy (iteration 17)

This project declares kind = "library" in wo.toml, so woc <dir> runs the FULL pipeline over it — parse, typecheck, interface satisfaction, ownership, GC inference — with no fn main required, and writes nothing. That retired iteration 16's woc --emit verification workaround. woc build on it fails naming the kind, unless a demo main is added (lib+bin is allowed).

• http/ — the public surface: Req/Resp and the response builders (types.wo), auth (auth.wo), multipart (multipart.wo), and the body-inspection pair media_type/form_values (form.wo).
• router/ — the route table and Logging.
• app.wo — App, the registration helpers, the dispatch loop.
• internal/ — not importable by a consumer. The connection-level request parser and carry-state record (parse.wo) and the serve loop, status text, and response serializer (serve.wo) live here. A consuming app that writes use writeonce-framework/internal gets WO-E108 at that use. The rule is Go's: a path segment named internal is refused across the [deps] boundary only — the framework's own modules import it freely.

One honest disclosure: privacy restricts NAMING, not code size. internal/ modules still compile into the consumer's single image (there is no dead-code elimination); a consumer simply cannot name them.

The consuming sample

docs/examples/web-app — a small storefront importing this framework through [deps]. Its acceptance (just web-app) exercises the whole chain: fetch → lock → build → serve → durable restart.