Test strictly smaller sub lists and classify results

sublistOf is also sometimes yielding the same list, so we discard same length prefixes. Also, classifying empty lists helps in ensuring we have actually non trivial cases.
cardano-scaling · Jul 11, 2023 · fbaa3eb · fbaa3eb
1 parent ffa4c9e
commit fbaa3eb
Showing 1 changed file with 9 additions and 8 deletions.
diff --git a/hydra-node/test/Hydra/CryptoSpec.hs b/hydra-node/test/Hydra/CryptoSpec.hs
@@ -16,6 +16,7 @@ import qualified Data.Map as Map
 import Hydra.Party (Party (vkey), deriveParty)
 import Test.Aeson.GenericSpecs (roundtripAndGoldenSpecs)
 import Test.QuickCheck (
+  classify,
   counterexample,
   elements,
   forAll,
@@ -104,11 +105,11 @@ specMultiSignature =
                 =/= Verified
 
     prop "does not validate multisig if less keys given" $ \sks (msg :: ByteString) -> do
-      (length sks > 1)
-        ==> forAll (sublistOf sks)
-        $ \prefix ->
-          let sigs = aggregate $ map (`sign` msg) (toList sks)
-           in verifyMultiSignature (map getVerificationKey prefix) sigs msg
-                =/= Verified
-                & counterexample ("Keys: " <> show prefix)
-                & counterexample ("Signature: " <> show sigs)
+      forAll (sublistOf sks) $ \prefix ->
+        (length prefix < length sks)
+          ==> let sigs = aggregate $ map (`sign` msg) (toList sks)
+               in verifyMultiSignature (map getVerificationKey prefix) sigs msg
+                    =/= Verified
+                    & classify (null prefix) "empty"
+                    & counterexample ("Keys: " <> show prefix)
+                    & counterexample ("Signature: " <> show sigs)