Created a safe inGPM function (branch)

gpm.cabal

@@ -2,7 +2,7 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 33fb8dc1910b29dc2948850dc3ab52f6a6c420a93c0113d1fc81076fcd555c3a
+-- hash: c6d39ec4e6cb0558da69c75830e9471b116c0dfabc6cdbaaefa819cea92298b1
 
 name:           gpm
 version:        0.1.0.0
@@ -32,6 +32,7 @@ library
   build-depends:
       base >=4.8 && <5
     , file-embed
+    , foldl
     , protolude
     , turtle
   default-language: Haskell2010
@@ -47,6 +48,7 @@ executable gpm
   build-depends:
       base >=4.8 && <5
     , file-embed
+    , foldl
     , gpm
     , protolude
     , turtle

package.yaml

@@ -27,6 +27,7 @@ dependencies:
 - protolude
 - turtle
 - file-embed
+- foldl
 library:
   source-dirs: src
 executables:

src/GPM.hs

@@ -5,8 +5,10 @@ module GPM
 where
 
 import           Data.FileEmbed (embedStringFile)
-import           Protolude      hiding (die, stdout, (%))
+import           Protolude      hiding (die, stdout, (%),fold)
 import           Turtle
+import qualified Control.Foldl as Fold
+import Control.Exception.Base (bracket)
 
 import           GPM.Review     (ReviewCommand (..), handleReview,
                                  parseReviewCmd)
@@ -16,8 +18,8 @@ gpm = do
   subcmd <- options "Git Project Manager" parser
   case subcmd of
    Init             -> init
-   NewIssue         -> newIssue
-   Review reviewCmd -> handleReview reviewCmd
+   NewIssue         -> inGPM newIssue
+   Review reviewCmd -> inGPM (handleReview reviewCmd)
 
 data Command = Init
              | NewIssue
@@ -31,6 +33,21 @@ parser = subcommand "init" "Initialize gpm" (pure Init)
                          "Review (use current branch by default)"
                          parseReviewCmd
 
+inGPM :: MonadIO io => IO a -> io ()
+inGPM actions = sh $ do
+  res <- fold (inshell "git rev-parse --abbrev-ref HEAD" empty) Fold.head
+  oldbr <- case res of
+    Nothing -> die "Cannot retrieve current branch"
+    Just br -> do
+           void $ inshell "git stash --all" empty
+           void $ inshell "git checkout gpm" empty
+           return br
+  liftIO $ bracket (return ())
+                   (const $ sh $ do
+                       void $ inshell ("git checkout " <> lineToText oldbr) empty
+                       void $ inshell "git stash pop" empty)
+                   (const actions)
+
 newIssue :: IO ()
 newIssue = die "TODO"