如何在Sqlite中使用Hspec/Yesod.Test？

cabal install hspec yesod-test

import Test.Hspec
import Yesod.Test
import Database.Persist.Sqlite
import Control.Monad.IO.Class (liftIO)
import MyApp (withApp)

spec :: Spec
spec = withApp $ do
  describe "GET /users" $ do
    it "responds with 200" $ do
      get ("/users" :: Text)
      statusIs 200

withApp :: SpecWith (TestApp App) -> Spec
withApp = before $ do
  pool <- liftIO $ createSqlitePool ":memory:" 10
  let settings = defaultSettings { connectionPool = pool }
  app <- liftIO $ withAppSettings settings $ return . fst
  return (TestApp app)

main :: IO ()
main = hspec spec