statedbtest

Overview ¶

Package statedbtest gives tests a fully migrated, empty state.db without migrating one.

It binds internal/dbtemplate to statedb.Open: the first test in a binary that asks for a database pays for one migration from scratch, and every test after it gets a copy of the result. A copy is the file statedb.Open would have produced — same schema, same schema_migrations rows, same file mode — so the code under test takes the path a hub takes when it opens an existing project, and none of the 56 migrations run again. Why that matters, in numbers, is in internal/dbtemplate's package comment.

Use it wherever a test needs a project or a database to exist and is not about how one comes to exist:

dir := statedbtest.Dir(t)              // a project directory, database migrated
statedbtest.SeedDir(t, dir)            // the same for a directory you already have
db := statedbtest.Open(t)              // a migrated *statedb.DB, closed at cleanup

Do not use it in a test about migrations, schema adoption, version skew or a first open racing another: those must build their database from scratch, or they stop testing what they are named for. pkg/statedb's in-package tests cannot import this package (it imports statedb); they bind dbtemplate themselves, in template_test.go. Its external statedb_test files use this package like everyone else.

The template is keyed on a SHA-256 of the migration files, and a freshly built template is checked against those files before it is ever copied: its schema_migrations must record exactly them, in order, and nothing else. It is built in memory, once per test binary, from the migrations that binary embeds, and is never written anywhere that outlives the binary — so it cannot go stale, and the check is what proves it rather than assumes it.