Add ob repl -c/--config option

ChangeLog.md

@@ -30,6 +30,7 @@ This project's release branch is `master`. This log is written from the perspect
   * [#949](https://github.com/obsidiansystems/obelisk/pull/949): Obelisk now configures its output and error streams to transliterate unsupported characters to a known-good replacement character.
   * [#951](https://github.com/obsidiansystems/obelisk/pull/951): Add `ob run --port` which allows the user to override the port on which the app is served, rather than always using the port configured in the route. This is compatible with the use of reverse proxies that do their own TLS termination, e.g. `ngrok`.
   * [#974](https://github.com/obsidiansystems/obelisk/pull/974): Fail `ob run` when invalid fields are present in `default-extensions`/`default-language`, or when Cabal files are otherwise invalid.
+  * [#1025](https://github.com/obsidiansystems/obelisk/pull/1025): Add `-c/--config` option to `ob repl`
 * obelisk-route
   * [#915](https://github.com/obsidiansystems/obelisk/pull/915): Add `routeLinkAttr` to `Obelisk.Route.Frontend`. This allows the creation of route links with additional, user-specified DOM attributes.
   * [#918](https://github.com/obsidiansystems/obelisk/pull/918): Add GHC 8.10.7 support for `obelisk-route`.

lib/command/src/Obelisk/Command.hs

@@ -91,7 +91,7 @@ data ObCommand
    | ObCommand_Run [(FilePath, Interpret)] (Maybe FilePath) (Maybe PortNumber)
    | ObCommand_Profile String [String]
    | ObCommand_Thunk ThunkOption
-   | ObCommand_Repl [(FilePath, Interpret)]
+   | ObCommand_Repl (Maybe FilePath) [(FilePath, Interpret)] -- user @.ghci@ config
    | ObCommand_Watch [(FilePath, Interpret)]
    | ObCommand_Shell ShellOpts
    | ObCommand_Doc String [String] -- shell and list of packages
@@ -120,7 +120,7 @@ obCommand cfg = hsubparser
       $ progDesc "Run current project in development mode"
     , command "profile" $ info (uncurry ObCommand_Profile <$> profileCommand) $ progDesc "Run current project with profiling enabled"
     , command "thunk" $ info (ObCommand_Thunk <$> thunkOption) $ progDesc "Manipulate thunk directories"
-    , command "repl" $ info (ObCommand_Repl <$> interpretOpts) $ progDesc "Open an interactive interpreter"
+    , command "repl" $ info (ObCommand_Repl <$> optional userGhciConfigOpt  <*> interpretOpts) $ progDesc "Open an interactive interpreter"
     , command "watch" $ info (ObCommand_Watch <$> interpretOpts) $ progDesc "Watch current project for errors and warnings"
     , command "shell" $ info (ObCommand_Shell <$> shellOpts) $ progDesc "Enter a shell with project dependencies or run a command in such a shell. E.g. ob shell -- ghc-pkg list"
     , command "doc" $ info (ObCommand_Doc <$> shellFlags <*> packageNames) $
@@ -276,6 +276,14 @@ shellFlags =
   <|> flag "ghc" "ghcjs" (long "ghcjs" <> help "Enter a shell having ghcjs rather than ghc")
   <|> strOption (short 'A' <> long "argument" <> metavar "NIXARG" <> help "Use the environment specified by the given nix argument of `shells'")
 
+userGhciConfigOpt :: Parser FilePath
+userGhciConfigOpt = strOption $ mconcat
+  [ long "config"
+  , short 'c'
+  , metavar "CONFIG"
+  , help "User .ghci config file (use at your own risk)"
+  ]
+
 interpretOpts :: Parser [(FilePath, Interpret)]
 interpretOpts = many
     (   (, Interpret_Interpret) <$>
@@ -440,7 +448,7 @@ ob = \case
     ThunkCommand_Pack config -> for_ thunks (packThunk config)
     where
       thunks = _thunkOption_thunks to
-  ObCommand_Repl interpretPathsList -> withInterpretPaths interpretPathsList runRepl
+  ObCommand_Repl mUserGhciConfig interpretPathsList -> withInterpretPaths interpretPathsList $ runRepl mUserGhciConfig
   ObCommand_Watch interpretPathsList -> withInterpretPaths interpretPathsList runWatch
   ObCommand_Shell (ShellOpts shellAttr interpretPathsList cmd) -> withInterpretPaths interpretPathsList $ \root interpretPaths -> do
     putLog Notice "Hint: use '--no-interpret path/to/dependency' to force building an unpacked dependency and include it in this shell."

lib/command/src/Obelisk/Command/Run.hs

@@ -208,7 +208,7 @@ run certDir portOverride root interpretPaths = do
     _ -> pure ()
   ghciArgs <- getGhciSessionSettings (pkgs <> manifestPkg) root
   freePort <- getFreePort
-  withGhciScriptArgs pkgs $ \dotGhciArgs -> do
+  withGhciScriptArgs [] pkgs $ \dotGhciArgs -> do
     runGhcid root True (ghciArgs <> dotGhciArgs) pkgs $ Just $ unwords
       [ "Obelisk.Run.run (Obelisk.Run.defaultRunApp"
       , "Backend.backend"
@@ -220,18 +220,19 @@ run certDir portOverride root interpretPaths = do
       , "}"
       ]
 
-runRepl :: MonadObelisk m => FilePath -> PathTree Interpret -> m ()
-runRepl root interpretPaths = do
+runRepl :: MonadObelisk m => Maybe FilePath -> FilePath -> PathTree Interpret -> m ()
+runRepl mUserGhciConfig root interpretPaths = do
   pkgs <- getParsedLocalPkgs root interpretPaths
   ghciArgs <- getGhciSessionSettings pkgs root
-  withGhciScriptArgs pkgs $ \dotGhciArgs ->
+  userCommands <- maybe (pure []) (fmap lines . liftIO . readFile) mUserGhciConfig
+  withGhciScriptArgs userCommands pkgs $ \dotGhciArgs ->
     runGhciRepl root pkgs (ghciArgs <> dotGhciArgs)
 
 runWatch :: MonadObelisk m => FilePath -> PathTree Interpret -> m ()
 runWatch root interpretPaths = do
   pkgs <- getParsedLocalPkgs root interpretPaths
   ghciArgs <- getGhciSessionSettings pkgs root
-  withGhciScriptArgs pkgs $ \dotGhciArgs ->
+  withGhciScriptArgs [] pkgs $ \dotGhciArgs ->
     runGhcid root True (ghciArgs <> dotGhciArgs) pkgs Nothing
 
 exportGhciConfig :: MonadObelisk m => FilePath -> PathTree Interpret -> m [String]
@@ -452,11 +453,13 @@ packageInfoToNamePathMap = Map.fromList . map (_cabalPackageInfo_packageName &&&
 -- Like 'withGhciScript' but provides the precise ghci arguments to add to a ghci session
 withGhciScriptArgs
   :: (MonadObelisk m, Foldable f)
-  => f CabalPackageInfo -- ^ List of packages to load into ghci
+  => [String] -- ^ User commands to insert into .ghci
+  -> f CabalPackageInfo -- ^ List of packages to load into ghci
   -> ([String] -> m ()) -- ^ Action to run with the extra ghci arguments
   -> m ()
-withGhciScriptArgs packageInfos f = withGhciScript loadPreludeManually packageInfos $ \fp ->
-  f ["-XNoImplicitPrelude", "-ghci-script", fp]
+withGhciScriptArgs userCommands packageInfos f =
+  withGhciScript (loadPreludeManually ++ userCommands) packageInfos $ \fp ->
+    f ["-XNoImplicitPrelude", "-ghci-script", fp]
   where
     -- These lines must be first and allow the session to support a custom Prelude when @-XNoImplicitPrelude@
     -- is passed to the ghci session.