dbtest

Overview ¶

Package dbtest gives each test BINARY (i.e. each Go package's test process) its own isolated, freshly-migrated PostgreSQL database.

Why: before this, every DB-touching package read the single OPENWATCH_TEST_DSN, ran migrations against that one shared database, and TRUNCATEd shared tables between tests. That works only when packages run serially — under package parallelism (`go test -p N`) two packages would truncate and write each other's rows mid-test. The whole suite therefore ran `-p 1`, serializing every DB package and dominating CI wall-clock.

With dbtest, package A's tests run against `owt_<hashA>` and package B's against `owt_<hashB>`, so they can't see each other and `-p N` is safe.

Speed: migrating ~35 migrations in every one of ~35 parallel package processes overwhelms Postgres. Instead dbtest migrates ONCE into a shared TEMPLATE database (keyed by a hash of the migration files, so it is rebuilt only when migrations change) and each package CLONEs it with `CREATE DATABASE ... TEMPLATE` — a fast file copy, no re-migration. A PostgreSQL advisory lock makes the one-time template build race-free across the parallel processes.

Usage — replace a package's hand-rolled `freshPool` body:

func freshPool(t *testing.T) *pgxpool.Pool {
	pool := dbtest.Pool(t)          // isolated, migrated, skips if no DSN
	// ... TRUNCATE the tables this package owns, as before ...
	return pool
}

Pool must be called DIRECTLY from the package's own test code (so the runtime caller resolves to that package's directory).