2490ef24

By: Tom Sydney Kerckhove <syd@cs-syd.eu>

Self-contained sanity-check specs; no TemplateDB in caller's outer

sqitchPostgresqlSpec and sqitchPersistentPostgresqlSpec no longer
require the caller to thread a TemplateDB through its outer-type stack
or to supply a ConnectionPool. Each check allocates a fresh empty
postgres database internally (its own server, user, and DB) and tears
it down on return. Phase 1 of the schema-equality check uses a second
fresh database, so the persistent baseline and the sqitch deploy are
isolated.

Spec combinator API:

  Before:
    sqitchPostgresqlSpec  :: SqitchSettings
                          -> TestDef (TemplateDB ': outers) ConnectionPool
                          -> TestDef outers a
    sqitchPostgresqlSpec' :: HContains outers TemplateDB
                          => SqitchSettings
                          -> TestDef outers ConnectionPool
                          -> TestDef outers ConnectionPool

  After:
    sqitchPostgresqlSpec  :: SqitchSettings
                          -> TestDef outers a
                          -> TestDef outers a

Same shape for sqitchPersistentPostgresqlSpec. The `'` variants are
removed; the spec combinator is now its own self-contained describe
block that callers compose with anything.

IO entry points take Postgres.Options rather than TemplateDB +
ConnectionPool:

  runSqitchPerChangeChecks   :: SqitchSettings -> Postgres.Options -> IO ()
  runSqitchWholePlanCycle    :: SqitchSettings -> Postgres.Options -> IO ()
  runSqitchPersistentChecks  :: SqitchPersistentSettings -> Postgres.Options -> IO ()

To support this, sydtest-persistent-postgresql 0.4.0.0 exports four
new building blocks: postgresqlServerSetupFunc, postgresqlUserSetupFunc,
postgresqlDatabaseSetupFunc, postgresqlPoolSetupFunc (these renamed
from internal-only adminDBSetupFunc/tempUserSetupFunc/
tempNewDatabaseSetupFunc/dbConnectionOptionsPoolSetupFunc); plus
emptyPostgresOptionsSetupFunc and emptyPostgresPoolSetupFunc that
chain them into "fresh empty database, returned as Postgres.Options or
as ConnectionPool".

sqitchTargetFromTemplateDB was replaced by sqitchTargetFromOptions
which builds a sqitch --target URI directly from Postgres.Options
(handling unix-socket hosts via URL-encoding as before).

Test fixtures and call sites updated. nix-ci-leader-database's
PostgreSQLSpec.hs needs a follow-up commit on the nix-ci side to
match.

Timeline