Define new property for validating CDDL conformance of ledger events.

  Also include a first (near empty) draft of a CDDL specification.

cardano-node/cardano-node.cabal

@@ -253,6 +253,7 @@ test-suite cardano-node-test
                       , cardano-ledger-core
                       , cardano-node
                       , cardano-slotting >= 0.1
+                      , cddl
                       , directory
                       , filepath
                       , hedgehog

cardano-node/ledger_events.cddl

@@ -0,0 +1,16 @@
+rule = ledger_event
+
+ledger_event =
+  [ (0, new_epoch)
+  // (1, body_event)
+  // (2, tick)
+  ]
+
+new_epoch =
+  #
+
+body_event =
+  #
+
+tick_event =
+  #

cardano-node/test/Test/Cardano/Node/LedgerEvent.hs

@@ -3,13 +3,20 @@
 module Test.Cardano.Node.LedgerEvent where
 
 import           Cardano.Node.LedgerEvent
+import qualified Codec.CBOR.Schema as CDDL
 import           Data.ByteString.Short(toShort)
 import           Data.ByteString.Lazy(fromStrict)
 import qualified Data.ByteString.Base16 as Hex
-import           Hedgehog (Property, discover, footnote)
+import qualified Data.Text.IO as TIO
+import           Hedgehog (Property, discover, footnote, (===))
 import qualified Hedgehog
 import qualified Hedgehog.Gen as Gen
 import qualified Hedgehog.Range as Range
+import           System.IO.Unsafe(unsafePerformIO)
+
+specification :: Text
+specification =
+  unsafePerformIO $ TIO.readFile "ledger_event.cddl"
 
 prop_roundtrip_LedgerEvent_CBOR :: Property
 prop_roundtrip_LedgerEvent_CBOR =
@@ -19,6 +26,14 @@ prop_roundtrip_LedgerEvent_CBOR =
     footnote ("serialized event: " <> show (Hex.encode $ serializeEvent version event))
     Hedgehog.tripping event (serializeEvent version) (deserializeEvent . fromStrict)
 
+prop_cddl_validation_LedgerEvent :: Property
+prop_cddl_validation_LedgerEvent =
+  Hedgehog.property $ do
+    version <- Hedgehog.forAll Gen.enumBounded
+    event <- Hedgehog.forAll genEvent
+    let bytes = serializeEvent version event
+    CDDL.validate specification bytes === Right ()
+
 genEvent :: Hedgehog.Gen AnchoredEvent
 genEvent =
   AnchoredEvent