Elaborate compatible governance parsers over all ShelleyBasedEra constructors

inEonForShelleyBasedEra infers its eon from the branch that consumes the
witness. In pCompatibleGovernanceCmds that was the experimental Era, whose
membership shrinks as eras are retired: once Conway leaves it, Conway would
silently take the pre-Conway branch and lose its governance commands, with no
compilation error.

Match on the ShelleyBasedEra constructors instead. The branches refine era to a
concrete one, so IsEra resolves directly and no experimental witness needs to be
threaded through this compatible module. pUpdateProtocolParametersCmd gets the
same treatment, dropping its ConwayEraOnwards witness and the convert round trip
to the experimental Era.

Author: Jimbo4350

cardano-cli/src/Cardano/CLI/Compatible/Governance/Option.hs

@@ -1,10 +1,11 @@
+{-# LANGUAGE GADTs #-}
+
 module Cardano.CLI.Compatible.Governance.Option
   ( pCompatibleGovernanceCmds
   )
 where
 
 import Cardano.Api
-import Cardano.Api.Experimental qualified as Exp
 
 import Cardano.CLI.Compatible.Governance.Command
 import Cardano.CLI.Compatible.Governance.Types
@@ -29,23 +30,29 @@ pCompatibleGovernanceCmds
 pCompatibleGovernanceCmds sbe =
   asum $
     catMaybes
-      [ inEonForShelleyBasedEra
-          ( subInfoParser
-              "governance"
-              ( Opt.progDesc $
-                  mconcat
-                    [ "Governance commands."
-                    ]
-              )
-              [ pCreateMirCertificatesCmds sbe
-              , pGovernanceGenesisKeyDelegationCertificate
-              , fmap CreateCompatibleProtocolParametersUpdateCmd <$> pGovernanceActionCmds sbe
-              ]
-          )
-          ( \w ->
-              fmap LatestCompatibleGovernanceCmds <$> Exp.obtainCommonConstraints w Latest.pGovernanceCmds
-          )
-          sbe
+      [ case sbe of
+          ShelleyBasedEraShelley -> preConway
+          ShelleyBasedEraAllegra -> preConway
+          ShelleyBasedEraMary -> preConway
+          ShelleyBasedEraAlonzo -> preConway
+          ShelleyBasedEraBabbage -> preConway
+          ShelleyBasedEraConway ->
+            fmap LatestCompatibleGovernanceCmds <$> Latest.pGovernanceCmds
+          ShelleyBasedEraDijkstra ->
+            fmap LatestCompatibleGovernanceCmds <$> Latest.pGovernanceCmds
+      ]
+ where
+  preConway =
+    subInfoParser
+      "governance"
+      ( Opt.progDesc $
+          mconcat
+            [ "Governance commands."
+            ]
+      )
+      [ pCreateMirCertificatesCmds sbe
+      , pGovernanceGenesisKeyDelegationCertificate
+      , fmap CreateCompatibleProtocolParametersUpdateCmd <$> pGovernanceActionCmds sbe
       ]
 
 pGovernanceActionCmds
@@ -64,7 +71,16 @@ pGovernanceActionCmds sbe =
 pUpdateProtocolParametersCmd
   :: ShelleyBasedEra era -> Parser (GovernanceActionProtocolParametersUpdateCmdArgs era)
 pUpdateProtocolParametersCmd sbe =
-  inEonForShelleyBasedEra (preConway sbe) postConway sbe
+  case sbe of
+    ShelleyBasedEraShelley -> preConway
+    ShelleyBasedEraAllegra -> preConway
+    ShelleyBasedEraMary -> preConway
+    ShelleyBasedEraAlonzo -> preConway
+    ShelleyBasedEraBabbage -> preConway
+    ShelleyBasedEraConway ->
+      mkCmd sbe (pure Nothing) (Just <$> pUpdateProtocolParametersPostConway)
+    ShelleyBasedEraDijkstra ->
+      mkCmd sbe (pure Nothing) (Just <$> pUpdateProtocolParametersPostConway)
  where
   -- The two branches build the same command and differ only in which of the two
   -- optional payloads they populate.
@@ -86,22 +102,8 @@ pUpdateProtocolParametersCmd sbe =
         )
       $ Opt.progDesc "Create a protocol parameters update."
 
-  preConway
-    :: ShelleyBasedEra era'
-    -> Parser (GovernanceActionProtocolParametersUpdateCmdArgs era')
-  preConway sbe' =
-    mkCmd sbe' (Just <$> pUpdateProtocolParametersPreConway) (pure Nothing)
-
-  postConway
-    :: ConwayEraOnwards era'
-    -> Parser (GovernanceActionProtocolParametersUpdateCmdArgs era')
-  postConway conwayOnwards =
-    mkCmd
-      (convert conwayOnwards)
-      (pure Nothing)
-      ( Just
-          <$> Exp.obtainCommonConstraints (convert conwayOnwards) pUpdateProtocolParametersPostConway
-      )
+  preConway =
+    mkCmd sbe (Just <$> pUpdateProtocolParametersPreConway) (pure Nothing)
 
 pUpdateProtocolParametersPreConway
   :: Parser (UpdateProtocolParametersPreConway era)