chore(users): grfn -> aspen r/7511

Change-Id: I6c6847fac56f0a9a1a2209792e00a3aec5e672b9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10809
Autosubmit: aspen <root@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: lukegb <lukegb@tvl.fyi>

1 files changed, 32 insertions, 0 deletions

diff --git a/users/aspen/xanthous/src/Xanthous/Util/QuickCheck.hs b/users/aspen/xanthous/src/Xanthous/Util/QuickCheck.hs
new file mode 100644
index 000000000000..aa881b322779
--- /dev/null
+++ b/users/aspen/xanthous/src/Xanthous/Util/QuickCheck.hs
@@ -0,0 +1,32 @@
+{-# LANGUAGE UndecidableInstances #-}
+module Xanthous.Util.QuickCheck
+  ( functionShow
+  , FunctionShow(..)
+  , functionJSON
+  , FunctionJSON(..)
+  , genericArbitrary
+  , GenericArbitrary(..)
+  ) where
+--------------------------------------------------------------------------------
+import Xanthous.Prelude
+import Test.QuickCheck
+import Test.QuickCheck.Function
+import Test.QuickCheck.Instances.ByteString ()
+import Test.QuickCheck.Arbitrary.Generic
+import Data.Aeson
+--------------------------------------------------------------------------------
+
+newtype FunctionShow a = FunctionShow a
+  deriving newtype (Show, Read)
+
+instance (Show a, Read a) => Function (FunctionShow a) where
+  function = functionShow
+
+functionJSON :: (ToJSON a, FromJSON a) => (a -> c) -> a :-> c
+functionJSON = functionMap encode (headEx . decode)
+
+newtype FunctionJSON a = FunctionJSON a
+  deriving newtype (ToJSON, FromJSON)
+
+instance (ToJSON a, FromJSON a) => Function (FunctionJSON a) where
+  function = functionJSON