Ensure proper handling of data files needed for testing

Author: lehins

cuddle.cabal

@@ -137,6 +137,7 @@ test-suite cuddle-test
   import: warnings
   default-language: GHC2021
   other-modules:
+    Paths_cuddle
     Test.Codec.CBOR.Cuddle.CDDL.Examples
     Test.Codec.CBOR.Cuddle.CDDL.Gen
     Test.Codec.CBOR.Cuddle.CDDL.Parser

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

@@ -13,14 +13,16 @@ import Codec.CBOR.Cuddle.CDDL.Resolve (
  )
 import Codec.CBOR.Cuddle.Parser (pCDDL)
 import Data.Text.IO qualified as T
+import Paths_cuddle (getDataFileName)
 import Test.HUnit (assertFailure)
 import Test.Hspec
 import Text.Megaparsec (parse)
 import Text.Megaparsec.Error (errorBundlePretty)
 
 tryValidateFile :: FilePath -> IO (Either NameResolutionFailure (CTreeRoot MonoReferenced))
 tryValidateFile filePath = do
-  contents <- T.readFile filePath
+  absoluteFilePath <- getDataFileName filePath
+  contents <- T.readFile absoluteFilePath
   cddl <- case parse pCDDL "" contents of
     Right x -> pure $ prependPrelude x
     Left x -> fail $ "Failed to parse the file:\n" <> errorBundlePretty x