Added Data.Incremental with class(ILC) and basic instances (Map,MonoidMap,Total) tests.

Added ILC instances for Core: Coin, UMap, DPState, DState, PState, UTxOState etc.
Added ILC instances for (Diff DPState), (Diff DState) (Diff UTxOstate) etc.
Add property tests for ILC invariants for every ILC instance.
Rewrote the "POOL" STS rule to use differences (Diff PState), and all the POOL tests
Added the Conway era HSpec test directory:  eras/conway/impl/test

Author: TimSheard

eras/conway/impl/cardano-ledger-conway.cabal

@@ -58,6 +58,7 @@ library
         aeson,
         bytestring,
         cardano-crypto-class,
+        cardano-data,
         cardano-ledger-binary >=1.1,
         cardano-ledger-allegra >=1.1,
         cardano-ledger-alonzo >=1.1,
@@ -97,3 +98,22 @@ library testlib
         cardano-ledger-core,
         cardano-ledger-mary:testlib,
         small-steps
+
+test-suite tests
+    type:             exitcode-stdio-1.0
+    main-is:          Main.hs
+    hs-source-dirs:   test
+    other-modules:    Test.Cardano.Ledger.Conway.DiffSpec
+    default-language: Haskell2010
+    ghc-options:
+        -Wall -Wcompat -Wincomplete-record-updates
+        -Wincomplete-uni-patterns -Wredundant-constraints -Wpartial-fields
+        -Wunused-packages -threaded -rtsopts -with-rtsopts=-N
+
+    build-depends:
+        base,
+        cardano-ledger-core:{cardano-ledger-core, testlib},
+        cardano-ledger-conway,
+        testlib,
+        cardano-ledger-core,
+        cardano-data:testlib

eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs

@@ -2,6 +2,7 @@
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
@@ -37,6 +38,7 @@ module Cardano.Ledger.Conway.Governance (
   GovernanceProcedure (..),
   Anchor (..),
   AnchorDataHash,
+  Diff (EnactState', RatifyState', ConwayGovernance'),
 ) where
 
 import Cardano.Crypto.Hash.Class (hashToTextAsHex)
@@ -74,6 +76,14 @@ import Data.Aeson (KeyValue, ToJSON (..), object, pairs, (.=))
 import Data.Aeson.Types (ToJSONKey (..), toJSONKeyText)
 import Data.ByteString (ByteString)
 import Data.Default.Class (Default (..))
+import Data.Functor.Identity (Identity)
+import Data.Incremental (
+  Diff (Total', Zero),
+  ILC (..),
+  Total,
+  applyTotal,
+  ($$),
+ )
 import Data.Map.Strict (Map)
 import Data.Sequence.Strict (StrictSeq)
 import Data.Set (Set)
@@ -438,6 +448,16 @@ data EnactState era = EnactState
   }
   deriving (Generic)
 
+instance ILC (EnactState era) where
+  newtype Diff (EnactState era) = EnactState' (Diff (Total (EnactState era)))
+  applyDiff x (EnactState' y) = applyTotal x y
+  extend (EnactState' x) (EnactState' y) = EnactState' $ extend x y
+  zero = EnactState' Zero
+  totalDiff x = EnactState' (Total' x)
+
+deriving instance Eq (PParamsHKD Identity era) => Eq (Diff (EnactState era))
+deriving instance Show (PParamsHKD Identity era) => Show (Diff (EnactState era))
+
 instance EraPParams era => ToJSON (EnactState era) where
   toJSON = object . toEnactStatePairs
   toEncoding = pairs . mconcat . toEnactStatePairs
@@ -453,8 +473,7 @@ toEnactStatePairs cg@(EnactState _ _ _ _ _ _) =
       , "withdrawals" .= ensWithdrawals
       ]
 
-deriving instance Eq (PParams era) => Eq (EnactState era)
-
+deriving instance (Eq (PParamsHKD Identity era), Eq (PParams era)) => Eq (EnactState era)
 deriving instance Show (PParams era) => Show (EnactState era)
 
 instance EraPParams era => Default (EnactState era) where
@@ -505,6 +524,29 @@ data RatifyState era = RatifyState
   }
   deriving (Generic, Eq, Show)
 
+instance ILC (RatifyState era) where
+  data Diff (RatifyState era) = RatifyState'
+    { diffRsEnactState :: !(Diff (EnactState era))
+    , diffRsFuture :: !(Diff (Total (StrictSeq (GovernanceActionId (EraCrypto era), GovernanceActionState era))))
+    }
+  applyDiff RatifyState {..} RatifyState' {..} =
+    RatifyState
+      { rsEnactState = rsEnactState $$ diffRsEnactState
+      , rsFuture = case diffRsFuture of
+          Zero -> rsFuture
+          Total' x -> x
+      }
+  extend x y =
+    RatifyState'
+      { diffRsEnactState = extend (diffRsEnactState x) (diffRsEnactState y)
+      , diffRsFuture = extend (diffRsFuture x) (diffRsFuture y)
+      }
+  zero = RatifyState' zero zero
+  totalDiff (RatifyState x y) = RatifyState' (totalDiff x) (Total' y)
+
+deriving instance EraPParams era => Eq (Diff (RatifyState era))
+deriving instance EraPParams era => Show (Diff (RatifyState era))
+
 instance EraPParams era => Default (RatifyState era)
 
 instance EraPParams era => DecCBOR (RatifyState era) where
@@ -549,6 +591,31 @@ data ConwayGovernance era = ConwayGovernance
   }
   deriving (Generic, Eq, Show)
 
+instance ILC (ConwayGovernance era) where
+  data Diff (ConwayGovernance era) = ConwayGovernance'
+    { diffCgTally :: !(Diff (Map (GovernanceActionId (EraCrypto era)) (GovernanceActionState era)))
+    , diffCgRatify :: !(Diff (RatifyState era))
+    , diffCgVoterRoles :: !(Diff (Map (Credential 'Voting (EraCrypto era)) VoterRole))
+    }
+  applyDiff ConwayGovernance {..} ConwayGovernance' {..} =
+    ConwayGovernance
+      { cgTally = ConwayTallyState (unConwayTallyState cgTally $$ diffCgTally)
+      , cgRatify = cgRatify $$ diffCgRatify
+      , cgVoterRoles = cgVoterRoles $$ diffCgVoterRoles
+      }
+  extend x y =
+    ConwayGovernance'
+      { diffCgTally = extend (diffCgTally x) (diffCgTally y)
+      , diffCgRatify = extend (diffCgRatify x) (diffCgRatify y)
+      , diffCgVoterRoles = extend (diffCgVoterRoles x) (diffCgVoterRoles y)
+      }
+  zero = ConwayGovernance' zero zero zero
+  totalDiff (ConwayGovernance (ConwayTallyState x) y z) =
+    ConwayGovernance' (totalDiff x) (totalDiff y) (totalDiff z)
+
+deriving instance (EraPParams era) => (Eq (Diff (ConwayGovernance era)))
+deriving instance (EraPParams era) => (Show (Diff (ConwayGovernance era)))
+
 cgTallyL :: Lens' (ConwayGovernance era) (ConwayTallyState era)
 cgTallyL = lens cgTally (\x y -> x {cgTally = y})
 

eras/conway/impl/test/Main.hs

@@ -0,0 +1,10 @@
+module Main where
+
+import Test.Cardano.Ledger.Common
+import Test.Cardano.Ledger.Conway.DiffSpec (conwayDiffSpecs)
+
+main :: IO ()
+main =
+  ledgerTestMain $
+    describe "Conway tests" $ do
+      conwayDiffSpecs

eras/conway/impl/test/Test/Cardano/Ledger/Conway/DiffSpec.hs

@@ -0,0 +1,31 @@
+{-# LANGUAGE TypeApplications #-}
+
+module Test.Cardano.Ledger.Conway.DiffSpec (conwayDiffSpecs) where
+
+import Cardano.Ledger.Conway (ConwayEra)
+import Cardano.Ledger.Conway.Governance
+import Cardano.Ledger.Crypto (StandardCrypto)
+import Test.Cardano.Data (
+  propExtend,
+  propZero,
+ )
+import Test.Cardano.Ledger.Common
+import Test.Cardano.Ledger.Conway.Arbitrary ()
+
+-- ==========================================================
+
+conwayDiffSpecs :: Spec
+conwayDiffSpecs = describe "ILC Diff tests" $ do
+  describe "Diff EnactState" $ do
+    propZero (arbitrary @(EnactState (ConwayEra StandardCrypto)))
+    propExtend (arbitrary @(EnactState (ConwayEra StandardCrypto))) arbitrary
+  describe "Diff RatifyState" $ do
+    propZero (arbitrary @(RatifyState (ConwayEra StandardCrypto)))
+    propExtend (arbitrary @(RatifyState (ConwayEra StandardCrypto))) arbitrary
+  describe "Diff GovernanceState" $ do
+    propZero (arbitrary @(GovernanceState (ConwayEra StandardCrypto)))
+    propExtend (arbitrary @(GovernanceState (ConwayEra StandardCrypto))) arbitrary
+
+-- To run theses tests in ghci, uncomment and type 'main'
+-- main :: IO ()
+-- main = hspec $ conwayDiffSpecs

eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Arbitrary.hs

@@ -1,5 +1,6 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE TypeFamilies #-}
@@ -8,6 +9,7 @@
 
 module Test.Cardano.Ledger.Conway.Arbitrary () where
 
+import Cardano.Ledger.BaseTypes (StrictMaybe)
 import Cardano.Ledger.Binary (Sized)
 import Cardano.Ledger.Conway.Core
 import Cardano.Ledger.Conway.Delegation.Certificates
@@ -17,6 +19,7 @@ import Cardano.Ledger.Conway.Rules
 import Cardano.Ledger.Conway.TxBody
 import Cardano.Ledger.Crypto (Crypto)
 import Control.State.Transition.Extended (STS (Event))
+import Data.Functor.Identity (Identity)
 import Test.Cardano.Ledger.Alonzo.Arbitrary ()
 import Test.Cardano.Ledger.Babbage.Arbitrary ()
 import Test.Cardano.Ledger.Common
@@ -230,3 +233,40 @@ instance
   Arbitrary (ConwayTickfEvent era)
   where
   arbitrary = undefined
+
+------------------------------------------------------------------------------------------
+-- Cardano.Ledger.Conway ILC instances ---------------------------------------------------
+------------------------------------------------------------------------------------------
+{-
+src/Cardano/Ledger/Conway/Governance.hs
+448:instance ILC (EnactState era) where
+521:instance ILC (RatifyState era) where
+584:instance ILC (ConwayGovernance era) where
+-}
+
+instance
+  ( Era era
+  , Arbitrary (PParamsHKD Identity era)
+  , Arbitrary (PParamsHKD StrictMaybe era)
+  ) =>
+  Arbitrary (Diff (EnactState era))
+  where
+  arbitrary = EnactState' <$> arbitrary
+
+instance
+  ( Era era
+  , Arbitrary (PParamsHKD Identity era)
+  , Arbitrary (PParamsHKD StrictMaybe era)
+  ) =>
+  Arbitrary (Diff (RatifyState era))
+  where
+  arbitrary = RatifyState' <$> arbitrary <*> arbitrary
+
+instance
+  ( Era era
+  , Arbitrary (PParamsHKD Identity era)
+  , Arbitrary (PParamsHKD StrictMaybe era)
+  ) =>
+  Arbitrary (Diff (ConwayGovernance era))
+  where
+  arbitrary = ConwayGovernance' <$> arbitrary <*> arbitrary <*> arbitrary

eras/conway/test-suite/cardano-ledger-conway-test.cabal

@@ -74,9 +74,10 @@ test-suite cardano-ledger-conway-test
         bytestring,
         cardano-ledger-allegra,
         cardano-ledger-alonzo,
+        cardano-data:testlib,
         cardano-ledger-babbage,
-        cardano-ledger-conway,
+        cardano-ledger-conway:{cardano-ledger-conway, testlib},
         cardano-ledger-conway-test,
-        cardano-ledger-core,
+        cardano-ledger-core:{cardano-ledger-core, testlib},
         cardano-ledger-shelley-test,
         tasty

eras/conway/test-suite/test/Tests.hs

@@ -4,6 +4,7 @@
 module Main where
 
 import Cardano.Ledger.Conway (Conway)
+import Test.Cardano.Ledger.Common (hspec)
 import qualified Test.Cardano.Ledger.Conway.Serialisation.CDDL as CDDL
 import qualified Test.Cardano.Ledger.Conway.Serialisation.Roundtrip as Roundtrip
 import Test.Tasty (TestTree, defaultMain, testGroup)

eras/shelley/impl/src/Cardano/Ledger/Shelley/Governance.hs

@@ -1,5 +1,7 @@
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE ScopedTypeVariables #-}
@@ -11,6 +13,7 @@
 module Cardano.Ledger.Shelley.Governance (
   EraGovernance (..),
   ShelleyPPUPState (..),
+  Diff (ShelleyPPUPState'),
 ) where
 
 import Cardano.Ledger.Binary (
@@ -23,13 +26,16 @@ import Cardano.Ledger.Binary (
 import Cardano.Ledger.Binary.Coders (Decode (..), decode, (<!))
 import Cardano.Ledger.Core
 import Cardano.Ledger.Crypto (Crypto)
+import Cardano.Ledger.Keys (KeyHash, KeyRole (..))
 import Cardano.Ledger.Shelley.Era (ShelleyEra)
-import Cardano.Ledger.Shelley.PParams (ProposedPPUpdates, emptyPPPUpdates)
+import Cardano.Ledger.Shelley.PParams (ProposedPPUpdates (..), emptyPPPUpdates)
 import Cardano.Ledger.TreeDiff (ToExpr)
 import Control.DeepSeq (NFData)
 import Data.Aeson (KeyValue, ToJSON (..), object, pairs, (.=))
 import Data.Default.Class (Default (..))
+import Data.Incremental (ILC (..), ($$))
 import Data.Kind (Type)
+import Data.Map (Map)
 import GHC.Generics (Generic)
 import NoThunks.Class (NoThunks (..))
 
@@ -72,6 +78,28 @@ data ShelleyPPUPState era = ShelleyPPUPState
   }
   deriving (Generic)
 
+instance ILC (ShelleyPPUPState era) where
+  data Diff (ShelleyPPUPState era) = ShelleyPPUPState'
+    { diffProposals :: !(Diff (Map (KeyHash 'Genesis (EraCrypto era)) (PParamsUpdate era)))
+    , diffFutureProposals :: !(Diff (Map (KeyHash 'Genesis (EraCrypto era)) (PParamsUpdate era)))
+    }
+  applyDiff ShelleyPPUPState {..} ShelleyPPUPState' {..} =
+    ShelleyPPUPState
+      { proposals = ProposedPPUpdates (unProposedPPUpdates proposals $$ diffProposals)
+      , futureProposals = ProposedPPUpdates (unProposedPPUpdates futureProposals $$ diffProposals)
+      }
+  extend x y =
+    ShelleyPPUPState'
+      { diffProposals = extend (diffProposals x) (diffProposals y)
+      , diffFutureProposals = extend (diffFutureProposals x) (diffFutureProposals y)
+      }
+  zero = ShelleyPPUPState' zero zero
+  totalDiff _ = ShelleyPPUPState' zero zero
+
+deriving instance Show (PParamsUpdate era) => Show (Diff (ShelleyPPUPState era))
+
+deriving instance Eq (PParamsUpdate era) => Eq (Diff (ShelleyPPUPState era))
+
 deriving instance Show (PParamsUpdate era) => Show (ShelleyPPUPState era)
 
 deriving instance Eq (PParamsUpdate era) => Eq (ShelleyPPUPState era)

eras/shelley/impl/src/Cardano/Ledger/Shelley/LedgerState.hs

@@ -94,6 +94,9 @@ module Cardano.Ledger.Shelley.LedgerState (
   lsUTxOStateL,
   utxosFeesL,
   utxosGovernanceL,
+
+  -- * ILC instances
+  Diff (IStake', UTxOState', LedgerState'),
 ) where
 
 import Cardano.Ledger.DPState