Add missing file

yesod-core/test/YesodCoreTest/Cache.hs

@@ -0,0 +1,50 @@
+{-# LANGUAGE QuasiQuotes, TypeFamilies, TemplateHaskell, MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE FlexibleInstances #-}
+module YesodCoreTest.Cache (cacheTest, Widget) where
+
+import Test.Hspec
+import Test.Hspec.HUnit()
+
+import Network.Wai
+import Network.Wai.Test
+
+import Yesod.Core
+
+data C = C
+
+key :: CacheKey Int
+key = $(mkCacheKey)
+
+key2 :: CacheKey Int
+key2 = $(mkCacheKey)
+
+mkYesod "C" [parseRoutes|/ RootR GET|]
+
+instance Yesod C where approot _ = ""
+
+getRootR :: Handler ()
+getRootR = do
+    Nothing <- cacheLookup key
+    cacheInsert key 5
+    Just 5 <- cacheLookup key
+    cacheInsert key 7
+    Just 7 <- cacheLookup key
+    Nothing <- cacheLookup key2
+    cacheDelete key
+    Nothing <- cacheLookup key
+    return ()
+
+cacheTest :: [Spec]
+cacheTest =
+  describe "Test.Cache"
+    [ it "works" works
+    ]
+
+runner :: Session () -> IO ()
+runner f = toWaiApp C >>= runSession f
+
+works :: IO ()
+works = runner $ do
+    res <- request defaultRequest { pathInfo = [] }
+    assertStatus 200 res