# Autoresearch lessons — Wavelet / Cordis quality run

Accumulated wisdom across iterations. Read this before forming a hypothesis.
Weight recent lessons higher: the yardstick and codebase change under us.

## Lesson 1 — iterations 0-1
**Pattern**: The project's committed gate (`golangci-lint run` with `.golangci.yml`)
had already been driven to 0 issues by a previous run, so it could no longer
measure anything.
**Why it worked**: Measuring against a pinned snapshot + extra analyzers in
`.auto/lint.ref.yaml` (hash-locked by the Guard) restored headroom and made it
impossible to lower the number by editing the config.
**Conditions**: Any repo whose own lint gate is already green.
**Anti-pattern**: Optimising `tagliatelle` (325 findings) or `wrapcheck` (290).
Those are pure cosmetics — error-message wording and tag naming. A run that
chases them will look productive while shuffling strings.
**Metric delta**: baseline re-established at 102 instead of a dead 0.

## Lesson 2 — iterations 1-4
**Pattern**: Triage every analyzer finding for reality before "fixing" it.
**Why it worked**: Three buckets turned out to be false positives:
`forcetypeassert` in `core/events.go` is guarded by `returnsErr` (the handler's
declared last out really is `error`), and both `exhaustive` switches already
have `default:` arms — `exhaustive` only flags them because
`default-signifies-exhaustive` defaults to false.
**Conditions**: Always, but especially for linters whose defaults assume a
different project convention.
**Anti-pattern**: Adding `if !ok { ... }` branches or empty `case:` arms that
cannot execute. That raises the score and lowers the code.
**Metric delta**: 3 of 16 candidate linters dropped from the plan (0 gained,
real regressions avoided).

## Lesson 3 — iterations 1, 4
**Pattern**: Pair the metric drop with a mechanically provable defect: write the
regression test, commit, then revert *only* the source files and require the
test to fail (`.auto/prove_fix.sh`).
**Why it worked**: It caught a live bug that no counter measures — a
singleflight body capturing the first caller's request context, so one
disconnecting browser poisoned every concurrent request for that image.
Iteration 4 kept debt flat at 93 yet was the most valuable change so far.
**Conditions**: Every behavioural fix. A change that survives its own revert is
not a fix, it is a rename.
**Anti-pattern**: Calling something "hardening" without a test that fails
without it.
**Metric delta**: 0 for the proven bug (kept under the fix gate), 8 for the rest.

## Lesson 4 — iteration 5
**Pattern**: Strengthen the architecture gate; it is a generator of real,
previously invisible debt.
**Why it worked**: `check_cordis_architecture.sh` only grepped `go func(`, so
`go w.run()` — the shape used by four long-lived cleanup loops — passed
silently, each one able to take down the process on a panic. Widening the
pattern surfaced them immediately.
**Conditions**: Whenever a gate has been green for a long time. A green gate
proves the checks exist, not that they cover anything.
**Anti-pattern**: Weakening `.golangci.yml` (blocked outright by the Guard via
`check_gate_weaken.py` + a SHA lock on the yardstick).
**Metric delta**: 4 uncovered crash-on-panic sites hardened.

## Lesson 5 — iteration 3
**Pattern**: Deduplicate by extracting the shared *classification*, not the
shared *response*.
**Why it worked**: Two handlers mapped upload-lookup errors with copy-pasted
blocks that had quietly drifted (different fallback status, different synonym
constant for the same message). `filesrv.AbortUploadRecordError` handles the
200/400 branches, and each endpoint keeps its own fallback it can still
justify. Deleting the orphaned `ErrInvalidUploadID` constant was part of the
change, not extra cleanup.
**Conditions**: Duplicated error-mapping or validation blocks in sibling handlers.
**Anti-pattern**: Silently unifying HTTP status codes across endpoints to make a
helper fit — that is a behaviour change wearing a refactor's clothes.
**Metric delta**: -2.

## Lesson 6 — iterations 15-21
**Pattern**: Delegate a broad read-only audit for what mechanical gates cannot
see (N+1s, locks held over I/O, resource leaks, layering), then re-verify each
claim yourself before touching code.
**Why it worked**: The audit produced the run's best findings — the per-request
CORS database query, the orphan cron dispatching to a task nobody registered,
media temp dirs nothing ever removed. It also produced a wrong one: it asserted
telebot falls back to `http.DefaultClient` with no timeout, when telebot itself
constructs a client with a one minute deadline. Acting on that would have added
a tunable dressed up as a bug fix.
**Conditions**: Whenever the committed gates are green and the easy signal is
exhausted.
**Anti-pattern**: Trusting an audit summary's file:line as evidence. One
referenced file did not exist.
**Metric delta**: 0 for three landed fixes (all kept under the proven-fix gate),
but they were the run's highest-impact changes.

## Lesson 7 — iteration 16
**Pattern**: Prove query-reduction with a functional test double that counts
loader invocations, and assert the counter for both the batch and the looped
form in the same test.
**Why it worked**: Asserting "1 query" alone is vacuous — it also passes when
nothing ran. Asserting batch=1 and per-id=3 in one test makes the instrument
itself checked, so the claim cannot silently degrade.
**Conditions**: Any change whose whole value is doing less I/O.
**Anti-pattern**: Fixing an N+1 by reaching around the contract into another
plugin's repository. The layering was the reason the slow path existed; the
right move was to extend the contract with a batch method.
**Metric delta**: 0 (kept under the proven-fix gate).

## Lesson 8 — iterations 17-22
**Pattern**: Strengthen a gate only alongside the code that satisfies it, and
never rewrite history in a shared worktree.
**Why it worked**: Deleting 24 dead lint suppressions paid off exactly as the
self-correcting design predicted: two of them were load-bearing under the
project's own gate even though the analyzer called them unused, the Guard
vetoed, and their removal surfaced two verified `contextcheck` false positives
worth documenting instead of silently swallowing. Meanwhile a concurrent
session was committing plan documents in the same tree, so `git add -A` swept
one of its in-flight edits into my commit — unfixable by rebase without
destroying their work, so the repair was to stage explicit paths from then on.
**Conditions**: Always, in this repo. Assume another agent is editing `docs/`
and `backend/core` concurrently.
**Anti-pattern**: `git add -A` outside the first setup commit. Also: trusting
"unused directive" as "safe to delete" — check the strictest config, not just
the pinned yardstick.
**Metric delta**: -25 in one iteration.

## Lesson 9 — iterations 23-24
**Pattern**: Cross-check every service a plugin's `Apply` reads out of the
container against what that plugin's `Inject()` declares. `Inject()` is the only
thing `App.reconcileLocked` gates on, so anything consumed as a *value* at Apply
time but left undeclared is resolved from a container that may not hold it yet.
**Why it worked**: It found the run's worst defect, invisible to every
mechanical gate: `user` declared only `DBService` while capturing
`contracts.AuthService` to build its route guard, and `cmd/app.go` lists `user`
before `auth`. Because user's dep set is a strict subset of auth's and it sits
earlier in the slice, user *always* mounts first — deterministically, not a
race — so `loginMW` fell back to a `c.Next()` closure and
`/api/v1/user/{change-password,profile,access-tokens}` mounted unguarded. The
same lookups in `admin` read a package global that its own `OnDispose` nils, so
in-flight requests fail open during dispose.
**Conditions**: Any Cordis plugin whose Apply assigns a contract result to a
variable used later (middleware, handler closures). Services bound through
`core.When` late binding are exempt — that is the correct pattern for genuinely
late deps, so do not blanket-declare everything.
**Anti-pattern**: Assuming a checked `x, ok :=` assertion is safe. All three
plugins used the checked form and all three failed *open* — checked syntax,
unchecked semantics.
**Metric delta**: 0 across both iterations (kept under the proven-fix gate),
but this is the run's highest-severity finding. `RouterRegistry` records each
route's `Handlers`/`Middlewares`, which makes "is this route actually guarded?"
directly assertable from the route table — the cheapest available oracle for
security properties here.

## Lesson 10 — iteration 23 review
**Pattern**: When the remaining metric is dominated by a positional or
taste-based analyzer, say so and refuse to spend iterations on it.
**Why it worked**: `funcorder` was 21 of 54 findings (39%) — pure function
*ordering within a file*. Reordering private helpers to the bottom of a file
moves the number and changes nothing a reader or the machine cares about, which
is Lesson 1's "looks productive while shuffling strings" with a different label.
Skipping it kept the loop honest. Triage also cleared 12 of 13
`forcetypeassert` (guarded by construction) and 2 of 3 `unparam` (deliberate
constructor symmetry behind one factory switch).
**Conditions**: Whenever one linter dominates a shrinking total, break the count
down per linter *before* picking a hypothesis.
**Anti-pattern**: Treating a large single-linter share as an easy win. Real
headroom at this point is ~10 findings, so a plateau in `debt` no longer means a
stalled loop.
**Metric delta**: 0 spent, ~21 findings deliberately left in place.

## Lesson 11 — iterations 24-25
**Pattern**: Run the Guard after every single commit, and confirm which commit a
proof script is actually reverting against.
**Why it worked**: Four `staticcheck ST1023` findings from iteration 24 shipped
straight through `go build ./...` and a green 47-package `go test ./...` —
neither runs the project linter, so only `checks.sh` section 3 catches them.
Separately, `prove_fix.sh` reverts to `HEAD^`; appending the iteration-23 log
commit shifted `HEAD^` to the *fixed* state and reported "PROVE FAILED: tests
still pass without the fix" on a genuinely load-bearing fix. Re-checking against
the explicit pre-fix commit (`git checkout <sha> -- <files>`) showed the real
answer. A false negative here is worse than no proof: it reads like the fix was
cosmetic.
**Conditions**: Always. Also note zsh does not word-split unquoted variables, so
`git checkout $FILES` passes one bogus pathspec and silently reverts nothing —
the command still exits 0.
**Anti-pattern**: Batch-verifying at ship time. And any shell loop built on the
bash word-splitting habit in this environment.
**Metric delta**: -0, 1 wrong verdict corrected.

## Lesson 12 — iterations 27-32
**Pattern**: Two things produced every substantive win: (1) find a place where
correctness rests on a *prose comment* instead of an enforced constraint, and (2)
find immutable startup work being redone inside a request path.
**Why it worked**: Lint cannot see either class, so `debt` barely moved while real
defects did. The comment "field comes from call sites, never from user input" sat
on a function that interpolated its column argument straight into `WHERE` — the
tautology payload executed and returned a row with `err=<nil>`, a filter bypass,
not a hypothetical. The comment "contracts are pure abstractions" sat on a DTO
carrying `TableName()`, which is exactly the handle four plugins used to read
`w_users` instead of calling `UserService`. On the second pattern, three packages
each re-normalised and re-split static whitelist patterns per request: hoisting
that to registration cut 14 allocs/op to 1.
**Conditions**: Any exported function taking a string that reaches SQL, a path
matcher, or a shell. Any loop over configuration inside a request handler.
**Anti-pattern**: Believing `nolintlint`'s "unused directive" means "safe to
delete" — hit twice now, and the project gate vetoed it both times. Also believing
a doc comment's self-assessment: verify the claim or leave it alone.
**Metric delta**: 64 -> 63 across five keeps. Four of the five kept changes had
delta 0. Under a pure-debt loop this run would have looked stalled while fixing a
security bypass and a hot-path allocation bug.

## Standing notes
- **The golangci-lint cache is machine-wide** (`~/.cache/golangci-lint`), so a
  sibling worktree analysing identical sources replays here carrying *that*
  checkout's absolute paths — 12 of 63 findings pointed outside the repo, which
  misattributes findings and can serve a stale Guard verdict. `measure.sh` and
  `checks.sh` now key `GOLANGCI_LINT_CACHE` per checkout (iteration 31). It is
  count-neutral (cold and warm both 63), but check path attribution before
  trusting any finding's location.
- **Do not delegate a repo-wide audit to one subagent.** Both broad audits
  (architecture, bugs/perf) hit the 150-turn cap after ~45M tokens combined and
  returned nothing usable. Everything this run found came from targeted inline
  greps followed by reading the specific function. If delegating, bound it to one
  package cluster and a small finding budget.
- Run decisions for this run: real defects first with `debt` as a secondary gate,
  commits directly on `main`, small file moves allowed but large package
  restructuring goes to a written proposal first.
- Upstream moves fast in this repo: `origin/main` gained 11 commits mid-run
  (Cordis config extension point — `ctx.Config().Bind`, `DeclareConfig()`,
  `core.ConfigGatedPlugin`), which raised measured `debt` 54 -> 64 and
  `nolint_dirs` 72 -> 73 on its own. Rebase early and re-run the Guard after;
  a clean rebase does not mean a green one.
- `cmd.TestNewWaveletAppWithRedisEnabled` needs a live Redis on
  `127.0.0.1:6379` and fails without one. Pre-existing on `origin/main`, so
  `tests_passed` 46 vs 47 is environmental, not a regression. Confirm against a
  scratch `git worktree` of `origin/main` before blaming a change for it.
- Repo facts: backend module rooted at `backend/`, gofumpt orders a single
  import group as `Wavelet/...` before stdlib (uppercase sorts first); new Go
  files need the Apache license header or `scripts/update_go_license.sh --check`
  fails the Guard.
- Handler edits require `make swagger` (cheap: it regenerates identical docs
  when only bodies change).
- Dead suppressions are tracked by the `nolint_dirs` counter; removing one that
  is still needed re-raises the original finding, so the metric self-corrects.
  24 were removed in iteration 22; 72 remain, each still doing work (73 after
  the upstream rebase).