Scotty with Persistent and Hspec-wai

Question

尝试单元化测试路由时出现问题。Scotty、Persistent和Hspec WAI。

与Yesod或Spock不同，Scotty没有一个很好的地方来存储数据库处理程序。我通过一个巨大的"do"来启动数据库，将数据库池保持为本地变量，然后使用该变量。

app :: IO ()
app = do
    -- allocate_database  $ pool
      -- scotty 8080 $do 
      --     handleSomeRoute pool

然而，Hspec WAI希望它出现在IO申请表中

scottyApp :: ScottyM () -> IO Application

有没有一种合理的方法将DB连接池注入scottyApp？

Answer 1

以下是如何做到这一点。基本上，在进行hspec调用之前打开数据库：

{-# LANGUAGE OverloadedStrings #-}
import           Test.Hspec
import           Test.Hspec.Wai
import           Network.Wai (Application)
import qualified Web.Scotty as S
allocate_db :: (Int -> IO a) -> IO a
allocate_db = undefined
handleSomeRoute :: Int -> S.ScottyM ()
handleSomeRoute = undefined
main2 :: IO ()
main2 = allocate_db $ pool -> do
  let app' = handleSomeRoute pool
  hspec $ with (S.scottyApp app') $ do
            describe "GET /" $ do
              it "responds with 200" $ do
                get "/" `shouldRespondWith` 200