yesodweb/yesod — comment on commit ce31a9c8abf18dacbdef455fea87bdd4a8acdad4
File:  line 0
By rianhunter:

hey michael, this code causes the following to break:

getHomeR :: Handler RepHtml
getHomeR = do
setSession "test" "value"
-- now this throws an exception and ignores accumulated session
-- instead of returning an Either in the inner monad
redirect RedirectTemporary SessionR

getSessionR :: Handler RepHtml
getSessionR = do
mKey <- lookupSession "test"
-- this throws a runtime exception because "test" wasn't in the session
let theValue = fromJust mKey
liftIO $ print theValue
defaultLayout [whamlet|foobar|]