[CBR-437] Add emptyPassphrase check

When the password is updated we should check if it is the
`emptyPassphrase` and, if so, update `HdRoot` to have no spending
password.

This commit also adds a test property that ensures the hdRoot has no
spending password afterwards, and modifies the existing property to only
test updates with non-empty passwords, where we expect the new hdRoot to
*have* a spending password.

Author: Anviking

wallet-new/src/Cardano/Wallet/Kernel/Wallets.hs

@@ -384,7 +384,15 @@ updatePassword pw hdRootId oldPassword newPassword = do
                                -- was set.
                                -- Fix this properly as part of [CBR-404].
                                lastUpdateNow <- InDb <$> getCurrentTimestamp
-                               let hasSpendingPassword = HD.HasSpendingPassword lastUpdateNow
+
+                               -- There is no such thing as "removing" the spending password.
+                               -- However, it can be set to the empty string. We check for that
+                               -- here and update 'hasSpendingPassword' on 'HdRoot' accordingly.
+                               let hasSpendingPassword =
+                                       if newPassword == emptyPassphrase
+                                       then HD.NoSpendingPassword
+                                       else HD.HasSpendingPassword lastUpdateNow
+
                                res <- update' (pw ^. wallets)
                                               (UpdateHdRootPassword hdRootId hasSpendingPassword)
                                case res of

wallet-new/test/unit/Test/Spec/Wallets.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE DataKinds        #-}
+{-# LANGUAGE LambdaCase       #-}
 {-# LANGUAGE TypeApplications #-}
 module Test.Spec.Wallets (
       spec
@@ -23,6 +24,7 @@ import qualified Cardano.Wallet.Kernel.BIP39 as BIP39
 import           Cardano.Wallet.Kernel.DB.HdWallet (AssuranceLevel (..),
                      HdRootId (..), UnknownHdRoot (..), WalletName (..),
                      hdRootId)
+import qualified Cardano.Wallet.Kernel.DB.HdWallet as HD
 import           Cardano.Wallet.Kernel.DB.HdWallet.Create
                      (CreateHdRootError (..))
 import           Cardano.Wallet.Kernel.DB.InDb (InDb (..))
@@ -327,6 +329,24 @@ spec = describe "Wallets" $ do
                                  newKey `shouldSatisfy` isJust
                                  (fmap hash newKey) `shouldSatisfy` (not . (==) (fmap hash oldKey))
 
+            prop "correctly updates hdRootHasPassword" $ do
+                monadicIO $ do
+                    newPwd <- pick arbitrary
+                    withNewWalletFixture $ \ _ _ wallet Fixture{..} -> do
+                        res <- Kernel.updatePassword wallet
+                                                     fixtureHdRootId
+                                                     (unV1 fixtureSpendingPassword)
+                                                     newPwd
+                        let passphraseIsEmpty = newPwd == emptyPassphrase
+                        let satisfied = \case
+                                        HD.NoSpendingPassword    -> passphraseIsEmpty
+                                        HD.HasSpendingPassword _ -> not passphraseIsEmpty
+                        case res of
+                             Left e -> fail (show e)
+                             Right (_, newRoot) -> do
+                                 (newRoot ^. HD.hdRootHasPassword) `shouldSatisfy` satisfied
+
+
         describe "Wallet update password (Servant)" $ do
             prop "works as expected in the happy path scenario" $ withMaxSuccess 50 $ do
                 monadicIO $ do