# Test-pruning campaign

Campaign mode prunes one subsystem's whole test surface in one PR: a plugin
such as `extensions/telegram`, or one core area. The value bar, retention bar,
candidate evidence, and validation in [SKILL.md](SKILL.md) apply to every
lane. This file adds the order of work and the lessons of a full campaign.
Each step ends on its completion criterion; do not start the next step early.

## 1. Baseline

Record the subsystem's test and support line counts and every test file's
pass/fail state at a pinned `main` SHA. Keep baseline failures in their own
list: they may be real product bugs rather than stale tests.

Done when every in-scope test file has a recorded baseline result.

## 2. Lanes and inventory

Split the surface into **lanes** along production owner boundaries, not file
prefixes. Example lanes include accounts, commands, dispatch, inbound,
outbound, persistence, transport, shared, harness, and live/QA scenarios.
Include the subsystem's cases at shared core boundaries and its QA
and live-proof harness tests.

Done when every test file and QA scenario the subsystem owns belongs to exactly
one lane.

## 3. Read-only ledger per lane

Use a read-only agent per lane when delegation is available and permitted;
otherwise inspect the lanes sequentially. The agent reads every assigned test
in full, including parameter tables. It also reads the production owners and
their entry points, callers, history, and CI routing. Each test declaration
goes into a written **ledger** with one mark. An `it.each` is one declaration
unless its rows need different marks; then mark each row.

- `R`: retain, naming the contract and the bug it catches; a retained test that
  only moves to a better-named file stays `R` with the move noted;
- `F`: retain the contract but repair the assertion, such as a vacuous negative
  that passes when only one of several items is missing;
- `C`: consolidate, naming the owner that absorbs the assertion first: a sibling
  table case, a stronger boundary suite, or the shared owner in another package;
- `D`: delete, naming the proof that remains, or why no contract exists.

Judge a test by its assertions, not its name. A test named for retiring a
progress window might only assert that the window was _not_ cleared.

Done when every declaration in the lane has a mark and an evidence line.

## 4. Layer plan per lane

Treat the per-test ledger as input, not as the edit list. A second read-only
pass, starting from the ledger, looks for the redundant **layer**. For example,
several dispatch suites may replay a shared compositor through one mocked
preview despite stronger real-stream and HTTP-fixture suites. Name the
**keeper** suite for each contract. Prefer the real transport boundary with a
fake network over a mocked collaborator. Correct any ledger errors this pass
finds.

Done when each lane plan names its retired files, its keeper per contract, the
assertions to carry into keepers, and the test-only production seams unlocked.

## 5. Cutover

Edit lane by lane. Serialize changes to shared harnesses and support files
through one owner. With each lane, remove the test-only production seams it
unlocks: injection parameters, getters, reset exports, and indirection layers.
Register moved suites in CI routing and test inventories. Update shrink-only
line-cap baselines. Put durable test-ownership rules in the subsystem's
`AGENTS.md`, drawn from mistakes this campaign actually found.

Done when every lane plan is applied and each lane's keepers pass.

## 6. Preservation review

Before claiming completion, have independent reviewers compare deleted
coverage against the keepers when delegation is available and permitted,
one reviewer per boundary group. Otherwise perform a separate preservation
pass and disclose the lack of independent review. They look for
contracts that lost their only proof. They also look for new assertions that
cannot fail, such as a rejection row the production code never reaches. The
review must distinguish a genuine lost contract from an unreachable assertion.

For each restored contract, make one deliberate **mutation** of the production
owner and confirm the keeper goes red. Then restore the source byte for byte.

Done when every reported gap is restored or rejected with source evidence, and
every restored contract has a caught mutation.

## 7. Product defects

A baseline failure that survives into a keeper is a bug report. Fix it at its
owner as a separate commit, and prove it through the real user flow, with a
**control** run that reverts the fix and shows the old behavior. Record
unrelated product discrepancies you find as follow-ups instead of fixing them
in the campaign.

Done when each repaired defect has a failing control and a passing candidate
on the same harness.

## 8. Reconcile and hand off

Campaigns can outlive many base-branch commits. Update from the base using
the repository's merge or rebase convention. When the base modified a file the
campaign deleted, preserve the new contract in the keeper before retaining
the deletion. Confirm every new regression added on the base still has a home.
Rerun the whole subsystem suite and repeat live proof on the reconciled head.

Expect review tooling to see a truncated file list on a diff this large.
Record maintainer decisions for generic compatibility flags in the PR evidence
rather than editing gates.

Hand off with the [SKILL.md](SKILL.md) report, plus:

- baseline and final test/support line counts, with production counted separately;
- lanes, retired layers, and keepers;
- preservation gaps found and their mutations;
- product defects with control and candidate proof.