Add positive generator tests for Huddle examples

Extract genAndValidateRule and genAndValidateCddl from genAndValidateFromFile
to enable reuse for testing Huddle schemas. Add "Generated value validates"
tests that verify generated CBOR values pass validation.

This exposes a bug in optionalMapExample where the generator cannot reliably
produce 10 unique keys from a 10-element range (1..10), causing most generated
maps to have fewer than the required 10 entries.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: Soupstraw

test/Test/Codec/CBOR/Cuddle/CDDL/GeneratorSpec.hs

@@ -30,7 +30,7 @@ import Test.Codec.CBOR.Cuddle.CDDL.Examples.Huddle (
   sizeBytesExample,
   sizeTextExample,
  )
-import Test.Codec.CBOR.Cuddle.CDDL.Validator (expectInvalid)
+import Test.Codec.CBOR.Cuddle.CDDL.Validator (expectInvalid, genAndValidateRule)
 import Test.Hspec (HasCallStack, Spec, describe, runIO, shouldBe, shouldSatisfy)
 import Test.Hspec.Core.Spec (SpecM)
 import Test.Hspec.QuickCheck (prop)
@@ -68,8 +68,25 @@ zapInvalidatesHuddle n huddle = do
   prop n . counterexample (TL.unpack . pShow $ mapIndex @_ @_ @MonoSimple cddl) $
     expectZapInvalidates cddl "root"
 
+-- | Test that generated values are valid for a Huddle schema
+genAndValidateHuddle :: String -> Huddle -> Spec
+genAndValidateHuddle n huddle = do
+  cddl <- tryResolveHuddle huddle
+  genAndValidateRule n "root" cddl
+
 spec :: Spec
 spec = do
+  describe "Positive generator" $ do
+    describe "Generated value validates" $ do
+      -- Note: simpleTermExample and refTermExample use custom generators
+      -- that intentionally produce type-mismatched values, so they're excluded
+      genAndValidateHuddle "opCert" opCertExample
+      genAndValidateHuddle "sizeText" sizeTextExample
+      genAndValidateHuddle "sizeBytes" sizeBytesExample
+      genAndValidateHuddle "rangeList" rangeListExample
+      genAndValidateHuddle "rangeMap" rangeMapExample
+      genAndValidateHuddle "optionalMapExample" optionalMapExample
+
   describe "Negative generator" $ do
     describe "Zapped value fails to validate" $ do
       zapInvalidatesHuddle "simpleTerm" simpleTermExample

test/Test/Codec/CBOR/Cuddle/CDDL/Validator.hs

@@ -6,6 +6,8 @@ module Test.Codec.CBOR.Cuddle.CDDL.Validator (
   spec,
   expectValid,
   expectInvalid,
+  genAndValidateCddl,
+  genAndValidateRule,
 ) where
 
 import Codec.CBOR.Cuddle.CBOR.Gen (generateFromName)
@@ -24,7 +26,7 @@ import Codec.CBOR.Cuddle.CDDL.CBORGenerator (CustomValidatorResult (..))
 import Codec.CBOR.Cuddle.CDDL.CTree (CTreeRoot (..))
 import Codec.CBOR.Cuddle.CDDL.CTree qualified as CTree
 import Codec.CBOR.Cuddle.CDDL.Postlude (appendPostlude)
-import Codec.CBOR.Cuddle.CDDL.Resolve (fullResolveCDDL)
+import Codec.CBOR.Cuddle.CDDL.Resolve (MonoReferenced, fullResolveCDDL)
 import Codec.CBOR.Cuddle.Huddle (
   Huddle,
   HuddleItem (..),
@@ -90,31 +92,42 @@ import Test.QuickCheck (
  )
 import Text.Megaparsec (runParser)
 
+-- | Test that a specific rule in a resolved CDDL generates valid values
+genAndValidateRule :: String -> Name -> CTreeRoot MonoReferenced -> Spec
+genAndValidateRule description name resolvedCddl =
+  prop description $ do
+    cborTerm <- runAntiGen $ generateFromName (mapIndex resolvedCddl) name
+    let
+      generatedCbor = toStrictByteString $ encodeTerm cborTerm
+      res = validateCBOR generatedCbor name (mapIndex resolvedCddl)
+      extraInfo =
+        unlines
+          [ "CBOR term:"
+          , prettyHexEnc $ encodeTerm cborTerm
+          ]
+    pure . counterexample extraInfo $ expectValid res
+
+-- | Test that all rules in a resolved CDDL generate valid values
+genAndValidateCddl :: String -> CTreeRoot MonoReferenced -> Spec
+genAndValidateCddl description resolvedCddl@(CTreeRoot m) = do
+  let
+    isRule CTree.Group {} = False
+    isRule _ = True
+  describe description $ do
+    forM_ (Map.keys $ Map.filter isRule m) $ \name@(Name n) ->
+      genAndValidateRule (T.unpack n) name resolvedCddl
+
 genAndValidateFromFile :: FilePath -> Spec
 genAndValidateFromFile path = do
   contents <- runIO $ T.readFile =<< getDataFileName path
   let
     cddl = fromRight (error "Failed to parse CDDL") $ runParser pCDDL path contents
     resolverError x =
       error $ "Failed to resolve the CDDL from file " <> show path <> ":\n" <> show x
-    resolvedCddl@(CTreeRoot m) =
+    resolvedCddl =
       either resolverError id . fullResolveCDDL . appendPostlude $
         mapCDDLDropExt cddl
-    isRule CTree.Group {} = False
-    isRule _ = True
-  describe path $ do
-    forM_ (Map.keys $ Map.filter isRule m) $ \name@(Name n) ->
-      prop (T.unpack n) $ do
-        cborTerm <- runAntiGen $ generateFromName (mapIndex resolvedCddl) name
-        let
-          generatedCbor = toStrictByteString $ encodeTerm cborTerm
-          res = validateCBOR generatedCbor name (mapIndex resolvedCddl)
-          extraInfo =
-            unlines
-              [ "CBOR term:"
-              , prettyHexEnc $ encodeTerm cborTerm
-              ]
-        pure . counterexample extraInfo $ expectValid res
+  genAndValidateCddl path resolvedCddl
 
 genInfiniteUniqueList :: Ord a => Gen a -> Gen [a]
 genInfiniteUniqueList = fmap nubOrd . infiniteListOf