Move Shelley commands to the top-lvl and deprecate "shelley" subcommand

cardano-cli/src/Cardano/CLI/Parsers.hs

@@ -35,7 +35,7 @@ parseClientCommand :: Parser ClientCommand
 parseClientCommand =
   asum
     [ parseByron <|> backwardsCompatibilityCommands
-    , parseShelley
+    , parseShelley <|> parseDeprecatedShelleySubcommand
     , parseDisplayVersion
     ]
 
@@ -51,15 +51,25 @@ parseByron =
          parseByronCommands
     ]
 
+-- | Parse Shelley-related commands at the top level of the CLI.
 parseShelley :: Parser ClientCommand
-parseShelley =
+parseShelley = ShelleyCommand <$> parseShelleyCommands
+
+-- | Parse Shelley-related commands under the now-deprecated \"shelley\"
+-- subcommand.
+--
+-- Note that this subcommand is 'internal' and is therefore hidden from the
+-- help text.
+parseDeprecatedShelleySubcommand :: Parser ClientCommand
+parseDeprecatedShelleySubcommand =
   subparser $ mconcat
-    [ commandGroup "Shelley specific commands"
+    [ commandGroup "Shelley specific commands (deprecated)"
     , metavar "Shelley specific commands"
     , command'
         "shelley"
-        "Shelley specific commands"
-        (ShelleyCommand <$> parseShelleyCommands)
+        "Shelley specific commands (deprecated)"
+        (DeprecatedShelleySubcommand <$> parseShelleyCommands)
+    , internal
     ]
 
 -- Yes! A --version flag or version command. Either guess is right!

cardano-cli/src/Cardano/CLI/Run.hs

@@ -11,6 +11,7 @@ import           Cardano.Prelude
 
 import           Control.Monad.Trans.Except.Extra (firstExceptT)
 import qualified Data.Text as Text
+import qualified Data.Text.IO as Text
 
 import           Cardano.CLI.Byron.Commands (ByronCommand)
 import           Cardano.CLI.Byron.Run (ByronClientCmdError, renderByronClientCmdError,
@@ -33,6 +34,10 @@ data ClientCommand =
     -- | Shelley Related Commands
   | ShelleyCommand ShelleyCommand
 
+    -- | Shelley-related commands that have been parsed under the
+    -- now-deprecated \"shelley\" subcommand.
+  | DeprecatedShelleySubcommand ShelleyCommand
+
   | DisplayVersion
   deriving Show
 
@@ -45,6 +50,10 @@ data ClientCommandErrors
 runClientCommand :: ClientCommand -> ExceptT ClientCommandErrors IO ()
 runClientCommand (ByronCommand c) = firstExceptT ByronClientError $ runByronClientCommand c
 runClientCommand (ShelleyCommand c) = firstExceptT (ShelleyClientError c) $ runShelleyClientCommand c
+runClientCommand (DeprecatedShelleySubcommand c) =
+  firstExceptT (ShelleyClientError c)
+    $ runShelleyClientCommandWithDeprecationWarning
+    $ runShelleyClientCommand c
 runClientCommand DisplayVersion = runDisplayVersion
 
 renderClientCommandError :: ClientCommandErrors -> Text
@@ -53,6 +62,26 @@ renderClientCommandError (ByronClientError err) =
 renderClientCommandError (ShelleyClientError cmd err) =
   renderShelleyClientCmdError cmd err
 
+-- | Combine an 'ExceptT' that will write a warning message to @stderr@ with
+-- the provided 'ExceptT'.
+ioExceptTWithWarning :: MonadIO m => Text -> ExceptT e m () -> ExceptT e m ()
+ioExceptTWithWarning warningMsg e =
+  liftIO (Text.hPutStrLn stderr warningMsg) >> e
+
+-- | Used in the event that Shelley-related commands are run using the
+-- now-deprecated \"shelley\" subcommand.
+runShelleyClientCommandWithDeprecationWarning
+  :: MonadIO m
+  => ExceptT e m ()
+  -> ExceptT e m ()
+runShelleyClientCommandWithDeprecationWarning =
+    ioExceptTWithWarning warningMsg
+  where
+    warningMsg :: Text
+    warningMsg =
+      "WARNING: The \"shelley\" subcommand is now deprecated and will be "
+        <> "removed in the future. Please use the top-level commands instead."
+
 runDisplayVersion :: ExceptT ClientCommandErrors IO ()
 runDisplayVersion = do
     liftIO . putTextLn $ mconcat