chore(tests): ensure only valid CryptoIDs are generated

test/FoundationSpec.hs

@@ -4,7 +4,6 @@ import TestImport
 
 import ModelSpec ()
 
-import qualified Data.CryptoID as CID
 import Yesod.EmbeddedStatic
 
 instance Arbitrary (Route Auth) where
@@ -110,9 +109,6 @@ instance Arbitrary (Route UniWorX) where
   arbitrary = genericArbitrary
   shrink = genericShrink
 
-instance Arbitrary a => Arbitrary (CID.CryptoID ns a) where
-  arbitrary = CID.CryptoID <$> arbitrary
-
 spec :: Spec
 spec = do
   parallel $ 

test/ModelSpec.hs

@@ -27,6 +27,8 @@ import Utils
 
 import Data.CryptoID.Poly
 import qualified Data.CryptoID.Class.ImplicitNamespace as Implicit
+import qualified Data.CryptoID.Class as Explicit
+import Data.Binary.SerializationLength
 
 import Control.Monad.Catch.Pure (Catch, runCatch)
 
@@ -172,6 +174,15 @@ instance {-# OVERLAPS #-} (HasCryptoID ns ct pt (ReaderT CryptoIDKey Catch), Arb
   arbitrary = arbitrary <&> \pt -> (pt, either (error . show) id . runCatch $ runReaderT (Implicit.encrypt pt) tmpKey)
     where
       tmpKey = unsafePerformIO genKey
+
+instance HasFixedSerializationLength () where
+  type SerializationLength () = 0
+
+instance HasCryptoID ns ct () (ReaderT CryptoIDKey Catch) => Arbitrary (CryptoID ns ct) where
+  arbitrary = return . either (error . show) id . runCatch $ runReaderT (Explicit.encrypt ()) tmpKey
+    where
+      tmpKey = unsafePerformIO genKey
+
 instance CoArbitrary ct => CoArbitrary (CryptoID ns ct)
 instance Function ct => Function (CryptoID ns ct)