This adds the measurement #154 has needed twice and never had. It does not fix the failure and does not guess at it: the issue has been wrong twice from reasoning ahead of evidence, and the point here is to make the next occurrence answer the question rather than reopen it.
The observation that rules out every explanation so far is that the schema comes back. A suite fails because orders does not exist, and a later suite truncating that same table passes. A dropped database does not un-drop itself, so this was never one database losing its schema. More than one server answering to one name produces exactly this, and Docker embedded DNS round-robins every container sharing an alias, so a leftover service container from an earlier run fits every observation including the empty dmesg that killed the OOM theory.
globalSetup now logs every address the database host resolves to. More than one is the answer outright. One address means this reading is wrong too, and the next suspect is a single container restarted with a fresh data directory.
Alongside it, both globalSetup and a failing assertSchemaPresent record which server actually answered. pg_postmaster_start_time is what settles that and needs no special rights: two Postgres instances cannot share one, so differing values within a single run are proof, where a differing inet_server_addr alone could be argued to be one container that moved. The failure message now says to compare the two rather than leaving the reader to know that is the interesting comparison.
Logged on a passing run as well as a failing one, deliberately. A failing run's addresses mean nothing without a passing run's to compare them against, and this issue has twice suffered from having only the failure to look at.
Neither can throw. A diagnostic that fails the run it was added to explain is worse than no diagnostic, so both are wrapped and both degrade to a printed reason.
The failure path costs one extra round trip, taken only when the schema is already known to be missing. assertSchemaPresent is not on the hot path — resetDb calls it only when its TRUNCATE has already failed.
Verified: tsc clean, typecheck:tests clean, lint 0 errors with no new warnings, and the four message patterns schemaLoss.integration.test.ts asserts on are all still present. The probe reads only pg_catalog functions, so it still answers against the dropped schema that suite creates.
Refs #154
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
When the integration run lost its schema partway through, it presented as 36 assertion errors about categories, price filters and favourite notifications. The real message — `relation "items" does not exist` — was further down the same log, and hours went into chasing the assertions instead.
The cause is still open and needs runner-side evidence this cannot reach: whether the Postgres service container is being recreated mid-run, which would come back with an empty data directory. This is the half that can be fixed from here — whatever the cause, the next occurrence reads as "the database lost its schema" on the first line, names which tables are gone, and says that nothing in the suite drops tables so the database was replaced underneath the run.
globalSetup asserts once after migrating, which establishes the fact the rest of the run depends on. Without it, a run that never had a schema and one that lost it midway are indistinguishable from the failures they produce.
resetDb checks only when its TRUNCATE fails, rather than on every reset. It runs in a beforeEach several hundred times a suite, and an extra round trip each time to guard against a rare event would be paying continuously for it. When the schema is fine, an unrelated failure is passed through untouched rather than dressed up as a schema problem.
The diagnostic is tested against a database that has actually lost its schema, not reasoned about. An earlier attempt dropped the schema before the run and proved nothing — globalSetup re-migrates, so it repaired itself and every test passed. The suite drops and rebuilds around each case and restores in afterAll; the full integration suite was then run twice to confirm the restore holds for everything ordered after it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
bermudalambandClaude Opus 5