Pinned aiken version and test to check plutus.json (#1777)

I noticed the `aiken` version used to generate the `plutus.json` is
different than the one provided through our flake. Consequently, the
re-built scripts would result in different hashes.

This PR pins to a specific aiken version in the flake and also adds a
test that ensures the serialized scripts in `plutus.json` are
deterministically created using this version.

Following this, I realized that the validators in the `plutus.json` were
even the result of manually invoking `aiken blueprint apply` and
interactively filling the commit script hash parameter on the initial
validator.

Instead of this error prone manual step, the `Hydra.Plutus` module now
applies parameters when providing the `initialValidatorScript`.

---

<!-- Consider each and tick it off one way or the other -->
* [x] CHANGELOG update not needed
* [x] Documentation update not needed
* [x] Haddocks update not needed
* [x] No new TODOs introduced

flake.nix

@@ -15,7 +15,7 @@
       url = "github:IntersectMBO/cardano-haskell-packages?ref=repo";
       flake = false;
     };
-    aiken.url = "github:aiken-lang/aiken";
+    aiken.url = "github:aiken-lang/aiken/v1.1.9";
     hls = {
       url = "github:haskell/haskell-language-server";
       flake = false;

hydra-plutus/hydra-plutus.cabal

@@ -109,8 +109,8 @@ test-suite tests
     , lens
     , lens-aeson
     , plutus-ledger-api
-    , process
     , QuickCheck
+    , typed-process
 
   build-tool-depends: hspec-discover:hspec-discover
 

hydra-plutus/src/Hydra/Plutus.hs

@@ -1,6 +1,12 @@
 {-# LANGUAGE TemplateHaskell #-}
 
 -- | Module to load and provide the Hydra scripts.
+--
+-- The plutus blueprint in 'plutus.json' is embedded in the binary and serves as
+-- the ground truth for validator scripts and hashes.
+--
+-- XXX: We are using a hardcoded indices to access validators in plutus.json.
+-- This is fragile and depends on the validator names not changing.
 module Hydra.Plutus where
 
 import Hydra.Prelude
@@ -10,44 +16,54 @@ import Data.Aeson qualified as Aeson
 import Data.Aeson.Lens (key, nth, _String)
 import Data.ByteString.Base16 qualified as Base16
 import Data.FileEmbed (embedFile, makeRelativeToProject)
-import PlutusLedgerApi.Common (SerialisedScript)
+import PlutusCore.Core (plcVersion110)
+import PlutusCore.MkPlc qualified as UPLC
+import PlutusLedgerApi.Common (SerialisedScript, serialiseUPLC, toBuiltin, toData, uncheckedDeserialiseUPLC)
+import PlutusLedgerApi.V3 (ScriptHash (..))
+import UntypedPlutusCore qualified as UPLC
 
--- | Loads the "plutus.json" blueprint and provides the decoded JSON.
+-- | Loads the embedded "plutus.json" blueprint and provides the decoded JSON.
 blueprintJSON :: Aeson.Value
 blueprintJSON =
   case Aeson.decodeStrict $(makeRelativeToProject "./plutus.json" >>= embedFile) of
     Nothing -> error "Invalid blueprint: plutus.json"
     Just value -> value
 
--- | Access the commit validator script from the 'blueprintJSON'.
+-- | Get the commit validator by decoding it from 'blueprintJSON'.
 commitValidatorScript :: SerialisedScript
 commitValidatorScript =
-  case Base16.decode commitBase16Bytes of
-    Left e -> error $ "Failed to decode commit validator: " <> show e
-    Right bytes -> toShort bytes
- where
-  commitBase16Bytes = encodeUtf8 base16Text
-  -- NOTE: we are using a hardcoded index to access the commit validator.
-  -- This is fragile and will raise problems when we move another plutus validator
-  -- to Aiken.
-  -- Reference: https://github.com/cardano-foundation/CIPs/tree/master/CIP-0057
-  base16Text = blueprintJSON ^. key "validators" . nth 0 . key "compiledCode" . _String
-
--- | Access the initial validator script from the 'blueprintJSON'.
+  toShort . Base16.decodeLenient . encodeUtf8 $
+    blueprintJSON ^. key "validators" . nth 0 . key "compiledCode" . _String
+
+-- | Get the commit validator hash from 'blueprintJSON'.
+commitValidatorScriptHash :: ScriptHash
+commitValidatorScriptHash =
+  ScriptHash . toBuiltin . Base16.decodeLenient . encodeUtf8 $
+    blueprintJSON ^. key "validators" . nth 0 . key "hash" . _String
+
+-- | Get the initial validator by decoding the parameterized initial validator
+-- from the 'blueprintJSON' and applying the 'commitValidatorScriptHash' to it.
 initialValidatorScript :: SerialisedScript
 initialValidatorScript =
-  case Base16.decode base16Bytes of
-    Left e -> error $ "Failed to decode initial validator: " <> show e
-    Right bytes -> toShort bytes
+  serialiseUPLC appliedProgram
  where
-  base16Bytes = encodeUtf8 initialBase16Text
-  initialBase16Text = blueprintJSON ^. key "validators" . nth 4 . key "compiledCode" . _String
+  appliedProgram = case unappliedProgram `UPLC.applyProgram` argumentProgram of
+    Left e -> error $ "Failed to applyProgram: " <> show e
+    Right x -> x
+
+  unappliedProgram = uncheckedDeserialiseUPLC unappliedScript
 
+  argumentProgram =
+    UPLC.Program () plcVersion110 $
+      UPLC.mkConstant () $
+        toData commitValidatorScriptHash
+
+  unappliedScript =
+    toShort . Base16.decodeLenient . encodeUtf8 $
+      blueprintJSON ^. key "validators" . nth 4 . key "compiledCode" . _String
+
+-- | Get the deposit validator by decoding it from 'blueprintJSON'.
 depositValidatorScript :: SerialisedScript
 depositValidatorScript =
-  case Base16.decode depositBase16Bytes of
-    Left e -> error $ "Failed to decode commit validator: " <> show e
-    Right bytes -> toShort bytes
- where
-  depositBase16Bytes = encodeUtf8 depositBase16Text
-  depositBase16Text = blueprintJSON ^. key "validators" . nth 2 . key "compiledCode" . _String
+  toShort . Base16.decodeLenient . encodeUtf8 $
+    blueprintJSON ^. key "validators" . nth 2 . key "compiledCode" . _String

hydra-plutus/test/Hydra/Plutus/GoldenSpec.hs

@@ -25,24 +25,32 @@ import Hydra.Cardano.Api (
  )
 import Hydra.Contract.Head qualified as Head
 import Hydra.Contract.HeadTokens qualified as HeadTokens
-import Hydra.Plutus (commitValidatorScript, depositValidatorScript, initialValidatorScript)
 import Hydra.Version (gitDescribe)
 import PlutusLedgerApi.V3 (serialiseCompiledCode)
 import PlutusLedgerApi.V3 qualified as Plutus
+import System.Process.Typed (runProcess_, shell)
 import Test.Hspec.Golden (Golden (..))
 
+aikenBuildCommand :: String
+aikenBuildCommand = "aiken build -t compact"
+
 spec :: Spec
 spec = do
+  it "Plutus blueprint is up-to-date" $ do
+    -- Running aiken -t compact should not change plutus.json
+    existing <- readFileBS "plutus.json"
+    runProcess_ $ shell aikenBuildCommand
+    actual <- readFileBS "plutus.json"
+    -- Undo any changes made by aiken
+    writeFileBS "plutus.json" existing
+    when (actual /= existing) $ do
+      putTextLn $ "Plutus blueprint in plutus.json is not up-to-date. Run " <> show aikenBuildCommand <> " to update it."
+    actual `shouldBe` existing
+
   it "Head validator script" $
     goldenScript "vHead" Head.validatorScript
   it "Head minting policy script" $
     goldenScript "mHead" (serialiseCompiledCode HeadTokens.unappliedMintingPolicy)
-  it "Deposit validator script" $
-    goldenScript "vDeposit" depositValidatorScript
-  it "Initial validator script" $
-    goldenScript "vInitial" initialValidatorScript
-  it "Commit validator script" $
-    goldenScript "vCommit" commitValidatorScript
 
 -- | Write a golden script on first run and ensure it stays the same on
 -- subsequent runs.