kanban: the terminal-status set (cancelled/failed) has no test that bites #2088

Implementation: FlyBot (ours) — PR follows within 24h. Do not pick up without a pickup-ok comment on this issue.

Written-by: FlyBot Lead
Claimed-by: FlyBot Lead
Claim-Id: 43b662f1ccbe42cdaa7cecd4225ac2f8
Branch: dev/3-kanban-terminal-statuses
Base: fca35af
At: 2026-11-02T00:49:41Z

Implementation: FlyBot (ours) — PR follows within 24h. Do not pick up without a pickup-ok comment.

Written-by: FlyBot Lead

What happens today

core/src/client/kanban.js decides when a Done card finished from a set of terminal actor statuses:

• :123 const TERMINAL_STATUSES = new Set(['accepted', 'cancelled', 'failed'])
• :125-126 const terminal = (task?.actors ?? []).find(entry => TERMINAL_STATUSES.has(entry?.status)) → terminal.at is the stamp

Nothing in core/test/kanban.test.js pins that set. The only stamping case (:671, a Done card says when it finished, from the first terminal actor entry) uses an accepted entry, so a card that was cancelled or failed can lose its finish time while the file stays green.

Measured on live main fca35af6f29a10214f239b78a2087b82845ba4ce, sources unchanged except the set:

const TERMINAL_STATUSES = new Set(['accepted']);

→ core/test/kanban.test.js 21 tests / 21 pass / 0 fail, exit 0, three runs identical. The cancelled/failed halves of the set can be deleted with a fully green file.

Reproduction

1. Check out live main fca35af6.
2. Narrow TERMINAL_STATUSES to ['accepted'] (or remove cancelled, then failed, one at a time) and run node --test core/test/kanban.test.js — all 21 original cases stay green.
3. Remove cancelled from COLUMN_OF instead: the card is not drawn in Done at all and no case notices.
4. Add blocked to TERMINAL_STATUSES: a card still in progress is stamped with a "finished" time and no case notices.

With the new cases present, the same mutations are bitten (25 / 23 / 2 for the shrink, 25 / 24 / 1 for each single-status mutation), so the case is the fix.

Expected behaviour

• A cancelled card in Done says when it was cancelled (its own terminal actor entry), not updatedAt.
• A failed card in Done says when it failed, likewise.
• blocked and result-ready are not terminal: the card stays In progress and gets no finish stamp.
• A non-terminal actor entry that sorts earlier does not take the stamp from the terminal one.

Scope

• core/test/kanban.test.js (new characterization cases only) and its generated mirror patches/ds-bot/files/test/kanban.test.js, kept byte-identical to each other.
• core/src/client/kanban.js and core/src/client/task-board.js are not changed: the behaviour is correct today, this issue adds the cases that bite when it regresses.
• No changelog fragment and no subsystem doc: nothing user-visible changes.
• The rail/counts region of the same test file is out of scope (#2086 / PR Test that the board rail counts the list the board draws #2087 adds its case around :435); this adds cases elsewhere in the file, no source file is shared.

Gates

• Red-first on the PR base, three identical runs: the shrink reds the new cases; the unmutated file is fully green.
• Per-mutation arms for cancelled, failed (both the set and COLUMN_OF), blocked, result-ready, claimed.
• TZ=UTC ARCH_DOCS_BASE=<base> npm run verify exit 0, > ok 10 patches apply cleanly in order, > ok core/ equals ds-bot/ + patches/ds-bot/, > build-client --check green, generate idempotent.
• Tier T1, effort XS (test-only, two mirrored files).

Duplicates

Searched live main and the issue tracker: TERMINAL_STATUSES appears only in #2077 (merged; the change that introduced the set) and #2066 (the original missing-stamp defect, closed). Closed-match also #1289. No open issue or PR covers the cancelled/failed coverage gap; the rail-counts gap next door is #2086.