Three spec decisions from Stephen (2026-10-13), each test-first:
- A child account has its parent's type (ParentTypeMismatch): a child
subdivides its parent. Test: a_child_account_has_its_parents_type.
- Periods nest (a month in a quarter in a year) but never partially
overlap (PeriodsOverlap; a refusal uses no id). Test:
periods_nest_but_never_partially_overlap.
- A line's account must exist and take postings when the line is added,
not only at post (UnknownAccount / PlaceholderAccount from add_line
and add_line_fx); posting still re-checks. Two older tests that pinned
the post-time refusal now check both (the post-time check is reached
through the unchecked replay path, as old journals can).
Compatibility: replay reads history through new Ledger::replay_*
commands (add_account, add_line, add_line_fx, create_period) that skip
checks added later, so books written before these rules still open.
The contract test books_written_under_older_rules_still_open writes such
a journal directly and found, on its first run, that the SQLite
cross-check rebuild used the checked commands and would have failed
verification ("sqlite projection can't be read back"); it now replays
too. Documented in docs/spec/README.md; decisions recorded in rules.md
(B-1, B-4, B-12).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
swaitsandClaude Opus 5.5
925c3ba523