用HSPEC测试酸态

Question

我是haskell noob，在用酸态进行测试功能方面存在问题。这是我的数据架构

data UserState = UserState { name :: String }
    deriving (Eq, Ord, Read, Show, Data, Typeable)

这是我要测试的功能：

setName :: String -> Update UserState String                  
setName n =      
    do c@UserState{..} <- get 
       let newName = n 
       put $ c { name = newName } 
       return newName
$(makeAcidic ''UserState ['setName ])

这是我的测试：

spec :: Spec
spec = do
  describe "test" $
    it "test" $ do
            setName "Mike" `shouldBe` UserState{ name = "Mike"}

我不知道如何建模我的预期值。UserState{ name = "Mike"}不起作用

Answer 1

我认为您无法访问数据库状态而无需查询它。因此，您需要添加查询以询问您的数据库状态，例如：

getUserState :: Query UserState UserState
getUserState = ask

然后可以写这样的测试：

withDatabaseConnection :: (AcidState UserState -> IO ()) -> IO ()
withDatabaseConnection = 
    bracket (openLocalState UserState{name = "initial name"}) 
            closeAcidState
spec :: Spec
spec = do
    around withDatabaseConnection $ do
        describe "test" $
            it "test" $ c -> do
                _ <- update c (SetName "Mike") 
                userState <- query c GetUserState
                userState `shouldBe` UserState{ name = "Mike"}