Expose API for fetching which migrations have run

[thdxr]

We're building a UI around running these migrations and need to know which migrations have already run without directly querying the migrations table

[koskimas]

What do you think about adding a getState method for the Migrator that returns an object like this

interface MigrationState {
  // All migrations sorted by name.
  readonly migrations: ReadonlyArray<NamedMigration>

  // Index of the last executed migration. -1 if no migrations have been executed.
  readonly currentIndex: number
}

interface NamedMigration extends Migration {
  readonly name: string
}

interface Migration {
  up(db: Kysely<any>): Promise<void>
  down?(db: Kysely<any>): Promise<void>
}

Or do you need other information about the migrations, like the execution timestamp?

[thdxr]

We'd probably like the timestamp but this works as a starting point

[koskimas]

Maybe it's more future-proof to add a getMigrations method for Migrator that returns a list of these:

{
  name: string
  migration: Migration
  executedAt?: Date
}

executedAt would be undefined for unexecuted migrations. Or should we add an executed boolean as well?

[koskimas]

Added in 0.16.9. https://koskimas.github.io/kysely/classes/Migrator.html#getMigrations