Add flag to clone a git repository recursive

src/Stack2nix.hs

@@ -53,9 +53,17 @@ stack2nix args@Args{..} = do
 
     tryGit :: FilePath -> IO ()
     tryGit tmpDir = do
-      void $ git $ OutsideRepo $ Clone argUri tmpDir
+      let externalCmd = if argGitRecursive
+                          then CloneRecursive argUri tmpDir
+                          else Clone argUri tmpDir
+      void . git $ OutsideRepo externalCmd
       case argRev of
-        Just r  -> void $ git $ InsideRepo tmpDir (Checkout r)
+        Just rev  ->
+          let internalCmd = if argGitRecursive
+                              then CheckoutRecursive rev 
+                              else Checkout rev
+          in
+            void . git $ InsideRepo tmpDir internalCmd
         Nothing -> return mempty
 
     handleStackConfig :: Maybe String -> FilePath -> IO ()

src/Stack2nix/External/VCS/Git.hs

@@ -6,11 +6,19 @@ module Stack2nix.External.VCS.Git
 import           Stack2nix.External.Util (failHard, runCmd, runCmdFrom)
 import           System.Exit             (ExitCode (..))
 
-data Command = OutsideRepo ExternalCmd
-             | InsideRepo FilePath InternalCmd
-data ExternalCmd = Clone String FilePath
-data InternalCmd = Checkout CommitRef
+data Command
+  = OutsideRepo ExternalCmd
+  | InsideRepo FilePath InternalCmd
 
+data ExternalCmd
+  = Clone RepoUri FilePath
+  | CloneRecursive RepoUri FilePath
+
+data InternalCmd 
+  = Checkout CommitRef
+  | CheckoutRecursive CommitRef
+
+type RepoUri = String
 type CommitRef = String
 
 exe :: String
@@ -24,7 +32,14 @@ git (InsideRepo dir cmd) = runInternal dir cmd
 runExternal :: ExternalCmd -> IO (ExitCode, String, String)
 runExternal (Clone uri dir) =
   runCmd exe ["clone", uri, dir] >>= failHard
+runExternal (CloneRecursive uri dir) =
+  runCmd exe ["clone", "--recurse-submodules", uri, dir] >>= failHard
 
 runInternal :: FilePath -> InternalCmd -> IO (ExitCode, String, String)
-runInternal repoDir (Checkout ref) =
-  runCmdFrom repoDir exe ["checkout", ref] >>= failHard
+runInternal repoDir (Checkout ref) = 
+  runCmdFrom repoDir exe ["checkout", ref]  >>= failHard
+runInternal repoDir (CheckoutRecursive ref) = do
+  checkoutCmd <- runCmdFrom repoDir exe ["checkout", ref] 
+  _ <- failHard checkoutCmd
+  submoduleCmd <- runCmdFrom repoDir exe ["submodule", "update", "--init", "--recursive"]
+  failHard submoduleCmd

src/Stack2nix/Types.hs

@@ -16,5 +16,6 @@ data Args = Args
   , argUri             :: String
   , argIndent          :: Bool
   , argVerbose         :: Bool
+  , argGitRecursive    :: Bool
   }
   deriving (Show)

stack2nix/Main.hs

@@ -26,6 +26,7 @@ args = Args
        <*> strArgument (metavar "URI")
        <*> flag True False (long "no-indent" <> help "disable indentation and place one item per line")
        <*> switch (long "verbose" <> help "verbose output")
+       <*> switch (long "git-recursive" <> help "clone external git reposity w/ all submodules")
   where
     -- | A parser for the date. Hackage updates happen maybe once or twice a month.
     -- Example: parseTime defaultTimeLocale "%FT%T%QZ" "2017-11-20T12:18:35Z" :: Maybe UTCTime