Make version picker a command

lib/SlackBuilder/LatestVersionCheck.hs

@@ -49,8 +49,10 @@ import Control.Monad.IO.Class (MonadIO(..))
 import Data.Char (isAlpha)
 import SlackBuilder.Download (responseBodySource, reqGet)
 import Network.HTTP.Client (BodyReader, Response(..))
-import Conduit (await)
-import Data.Conduit.Process (sourceCmdWithStreams)
+import Conduit (decodeUtf8C, (.|), linesUnboundedC, sinkNull)
+import qualified Data.Conduit.List as CL
+import Data.Conduit.Process (sourceProcessWithStreams, proc)
+import Data.Maybe (listToMaybe)
 
 data PackageOwner = PackageOwner
     { owner :: Text
@@ -195,27 +197,29 @@ latestPackagist PackageOwner{..} = do
 -- * Remote text file
 
 data TextArguments = TextArguments
-    { versionPicker :: Either (Text -> Text) [Text]
-    , textURL :: Text
+    { textURL :: Text
+    , versionPicker :: [String]
     }
 
 latestText :: TextArguments -> SlackBuilderT (Maybe Text)
 latestText TextArguments{..} = do
     case versionPicker of
-        Left versionPicker' -> do
+        (command : arguments) -> do
+            uri' <- mkURI textURL
+            runReq defaultHttpConfig $ reqGet uri' $ readResponse command arguments
+        [] -> do
             uri <- liftIO $ useHttpsURI <$> mkURI textURL
 
             packagistResponse <- traverse (runReq defaultHttpConfig . go . fst) uri
-            pure $ versionPicker' . Text.Encoding.decodeUtf8 . Network.HTTP.Req.responseBody
+            pure $ Text.strip . Text.Encoding.decodeUtf8 . Network.HTTP.Req.responseBody
                 <$> packagistResponse
-        Right _ -> do
-            uri' <- mkURI textURL
-            runReq defaultHttpConfig $ reqGet uri' readResponse
   where
-    readResponse :: Response BodyReader -> IO (Maybe Text)
-    readResponse response = do
-        (_, stdout', _) <- sourceCmdWithStreams "grep -oh 'Linux—[[:digit:].]\\+'" (responseBodySource response) await (pure ())
-        pure $ Text.drop 6 . head . Text.lines . Text.Encoding.decodeUtf8 <$> stdout'
+    readResponse :: String -> [String] -> Response BodyReader -> IO (Maybe Text)
+    readResponse command arguments response = do
+        let createProcess' = proc command arguments
+        (_, stdout', _) <- sourceProcessWithStreams createProcess' (responseBodySource response) stdoutReader sinkNull
+        pure $ Text.drop 6 <$> listToMaybe stdout'
+    stdoutReader = decodeUtf8C .| linesUnboundedC .| CL.consume
     go uri = req GET uri NoReqBody bsResponse mempty
 
 -- * GitHub