Yesod: returning a static file if path for dynamic contents is wrong. This code set Status to 200.

gistfile1.hs

{-# LANGUAGE OverloadedStrings, QuasiQuotes, TemplateHaskell, TypeFamilies #-}
import Yesod
import Network.HTTP.Types (status200)

data App = App

mkYesod "App" [parseRoutes|
/home HomeR GET
|]

instance Yesod App where
    errorHandler NotFound = sendResponseStatus status200
                          $ TypedContent typeHtml
                          $ ContentFile "not-found.html" Nothing
    errorHandler x = defaultErrorHandler x

getHomeR :: Handler Html
getHomeR = defaultLayout [whamlet|<p>Weird place for a homepage|]

main :: IO ()
main = warpEnv App