core/database holds the four entities from PRODUCT_PLAN.md §10 —
period_records, spotting_records, prediction_records, not_yet_observations —
with DAOs returning Flow, epoch-day/epoch-milli converters, and the schema
exported to core/database/schemas and committed.
Three constraints are structural rather than remembered:
- startDate is UNIQUE and inserts ABORT rather than REPLACE. REPLACE would
delete the original row with its createdAt and source; §14 says health
history is never modified silently.
- spotting has its own table, so no query for periods can reach it. §25: it
must never start or reset a cycle.
- a prediction snapshot can be scored but not rewritten — score() sets only
actualStartDate and absoluteErrorDays. A snapshot editable after the fact
can only ever report that the app was right, which would make §16's whole
accuracy feature a lie.
deleteEverything() is one transaction and the only bulk delete in the module: a
partial wipe leaves the cycle reconstructible from the tables the user asked to
be rid of.
14 tests, on the JVM under Robolectric — no emulator.
THE SCHEMA GUARD, AND WHY IT IS A SCRIPT
SchemaTest was written as a drift guard and proved not to be one. Room
regenerates the schema export during compilation, so adding a column to
PeriodRecordEntity without bumping VERSION leaves the suite green while the
committed schema quietly changes underneath it. That was not reasoned about, it
was run: the column was added, 1.json gained it, and every test passed. On a
device that is "Room cannot verify the data integrity" — a crash on update,
after shipping.
scripts/schema-guard.sh asks git instead, which Room cannot overwrite. Proved
both ways before being trusted: green on a clean tree, exit 1 on the injected
drift. It runs in pre-commit when an entity or the schema directory is staged,
and the hook treats its exit 2 as a refusal.
SchemaTest keeps its four tests and now documents what it does not catch.
Room's own MigrationTestHelper is not used: every constructor needs an
Instrumentation and schema assets, and AGP 9's library source-set DSL throws
DefaultAndroidLibrarySourceSet_Decorated cannot be cast to
AndroidLibrarySourceSet when you add an asset directory. Recorded so the next
person does not spend the afternoon on it.
Docs updated in this commit, as their triggers required: the migration table
now has its version 1 row and the trap that makes such tables go stale, TOOLS
explains the seventh script, and the hooks README lists the new guard.
closes#3
67b3c45002