Round 3 over round 2's fixes. The trend is 22 → 13 → 6, and the character has
shifted: these are mostly defects in the REVIEW's own work, not in the epic.
The ordering test I added to hold the middleware's position could not fail for
either arrangement it names. All four `@app.middleware("http")` layers — the
access log, the two header decorators AND the setup gate that must be inside —
register as the same `BaseHTTPMiddleware`, so asserting on the class passes for
the pre-move stack and for a cap moved back outside CORS. It names the layers by
their dispatch function now, which is the only thing that distinguishes them.
The `sysconfig` bounds check CLAMPED, and clamping is a silent rewrite — the thing
this module refuses to do everywhere else, where an unusable override falls back
to the env default and logs once. On the max side the difference is cosmetic; on
the min side it is a live bug. `download_upload_max_bytes` had `min=0` before E7,
and a stored 0 means "no per-file cap" to the route that reads it. Clamped to 1 it
becomes a ONE-BYTE cap: uploads dead, nothing in the log, the admin page showing
"1". It raises `OutOfRange` now and takes the existing fallback, with its own
event code.
The `capped_body` sweep grepped for an identifier as the limit argument, so a site
written `capped_body(request, 4 * 1024 * 1024)` — or with the parameter not named
`request` — was MISSED, and a miss reads as "no new sites". Parsed with `ast`
instead: every call is seen whatever it looks like, and an unfamiliar argument
shape fails the equality instead of vanishing.
Frontend: the shrink test drove the mock in a way the real hook cannot produce
(it moved `visible` in the same step as the shrink, and the comment miscounted the
tags), so it reproduced the right END STATE by accident rather than the sequence.
`visible` is now left alone across the shrink, which IS the precondition.
Ops: the baseline guard answered "did this run rewrite it?" and therefore went
green on the second run over an already-tightened, uncommitted baseline — the
exact state its own comment says marks the localdev stack stale ever after. It
asks both questions now. And `.dockerignore` joins BAKED_PATHS: it decides what
the COPY lines actually take, so it is an input to the build context exactly as
the copied trees are.
Backend conventions
The rules below are already followed across backend/app — they lived only in a few module
docstrings (demo.py, userscope.py, routes/_common.py) until this file collected them (E3 S3,
B-core-20). When you add code, match these so the next reader doesn't have to guess "which pattern do
I copy".
Module layering
Three layers, by who runs the code — not by feature:
-
routes/…— request-only. A route module holds HTTP concerns: auth dependencies, request/ response models, status-code mapping, serialization. It owns logic that runs only on a request. Business logic that a request happens to trigger does not live here if anything else runs it too. -
plex/,downloads/,sync/,issues/— domain logic shared by more than one caller. Anything the scheduler or the worker runs (not just a request) lives in one of these domain packages, so the route, the worker, and the scheduler share one definition. Examples from this codebase:downloads/service.pyowns enqueue + the job state transitions (routes call it);plex/sync.pyis run by both the admin route and the scheduler;downloads/pipeline.pyis the worker's child pipeline;issues/bundle.pyis the one definition of a bug report's files, for the zip export and the tracker. -
Flat
app/*.pycore modules — cross-cutting primitives.auth,sysconfig,quota,audit,notifications,userscope,realtime,ratelimit,progress,logs(the one logging configuration),logsink(itslog_eventstable),diagnostics(a user's consented log level) anddebugsession(a recording that tags its user's lines, E16), … are single-file primitives many layers import. They depend on nothing above them (a core module must never import aroutes/…module).
Extraction trigger: the SECOND consumer. Keep new logic inline in its first caller. The moment a second caller needs it (a worker as well as a route; a scheduler as well as a route), extract it down a layer — into the relevant domain package, or a flat core module if it's cross-cutting. Don't pre-abstract for a single caller; don't leave shared logic duplicated once there are two.
Transaction ownership
This follows CLAUDE.md's canonical rule verbatim — "the handler/job-wrapper commits; helpers flush
(only quota owns its session)" — so read it that way, not as an exception to it. The commit belongs
to the operation owner; anything called inside another transaction only stages its change
(db.add / flush) and lets the owner commit, so the whole operation is one transaction.
audit.record() is the reference: it adds the audit row and the caller commits it together with the
mutation it records, so an audit entry can never exist without its change (or vice-versa).
- The operation owner is usually the route handler. A
service.*operation the handler delegates a whole transition to (e.g.service.cancel) is that owner and commits its one transition — it isn't a mid-operation helper. A helper that owns its OWN short-lived session (the worker'sjobdbwrites, the same carve-out CLAUDE.md grantsquota) commits that session. Everything else flushes. SessionLocalisexpire_on_commit=False: after a rawUPDATE+ commit, an ORM object you already loaded is stale. Read the fresh value from the row (RETURNING, or a re-SELECT), not the ORM attribute — seeservice.decr_ref_count.
Shared counters and status: do it atomically at the DB
- Never read-modify-write a shared counter in Python (
x.count = x.count + 1). Concurrent sessions lose an update. Use a DB-atomic statement —col = col + 1, orgreatest(col - 1, 0)withRETURNINGso the caller branches on the post-value under the row lock (service.incr_ref_count/decr_ref_count). - Download job status is a
JobStatusStrEnum (downloads/status.py), not bare strings. TheHOLDINGset defines which states hold aMediaAsset(so release accounting stays correct);STOPPED_BY_ROUTEis the route-initiated stop set. A worker child's terminal write goes throughservice.finalize_if_running(an atomicUPDATE … WHERE status='running') so a finishing child can't resurrect a job a route just stopped.
Config: one home per kind
app.config.settings— boot/env config (DB URL, download root, worker concurrency): read once at startup, not user-tunable at runtime.sysconfig.SPECS— the runtime admin knobs (DB-override-or-default). A new admin-tunable value goes inSPECS; don't invent a fourth store. (state.py'smaintenance_batchpredates this and is slated to fold intosysconfig— do not add more like it.)
The gate
Everything below must be green before a change is done (run via siftlode check):
ruff (backend) · tsc ×3 + eslint + prettier + knip (frontend) · vitest · pytest. The
pytest lane runs in backend/docker-compose.test.yml — an ephemeral Postgres + the backend tree
bind-mounted — so the DB-backed integration tests (the db fixture) actually run; SIFTLODE_TEST_ REQUIRE_DB=1 there turns a would-be silent skip into a hard failure. See docs/development.md.