Add compile-proto-file helper cli tool (#87)

* Add compile-proto-file helper cli tool (.proto -> ast -> .hs)

* Update default.nix

default.nix

@@ -1,7 +1,8 @@
 { mkDerivation, async, base, bytestring, c2hs, clock, containers
-, grpc, managed, pipes, proto3-wire, protobuf-wire, QuickCheck
-, random, safe, sorted-list, stdenv, stm, tasty, tasty-hunit
-, tasty-quickcheck, text, time, transformers, turtle, unix, vector
+, grpc, managed, optparse-generic, pipes, proto3-wire
+, protobuf-wire, QuickCheck, random, safe, sorted-list, stdenv, stm
+, system-filepath, tasty, tasty-hunit, tasty-quickcheck, text, time
+, transformers, turtle, unix, vector
 }:
 mkDerivation {
   pname = "grpc-haskell";
@@ -17,15 +18,15 @@ mkDerivation {
   librarySystemDepends = [ grpc ];
   libraryToolDepends = [ c2hs ];
   executableHaskellDepends = [
-    async base bytestring containers proto3-wire protobuf-wire random
-    text transformers
+    async base bytestring containers optparse-generic proto3-wire
+    protobuf-wire random system-filepath text transformers turtle
   ];
   testHaskellDepends = [
     async base bytestring clock containers managed pipes protobuf-wire
     QuickCheck safe tasty tasty-hunit tasty-quickcheck text time
     transformers turtle unix
   ];
-  homepage = "http://github.com/aloiscochard/grpc-haskell";
+  homepage = "https://github.mv.awakenetworks.net/awakenetworks/gRPC-haskell";
   description = "Haskell implementation of gRPC layered on shared C library";
   license = stdenv.lib.licenses.asl20;
 }

grpc-haskell.cabal

@@ -93,6 +93,24 @@ library
     CPP-Options: -DDEBUG
     CC-Options:  -DGRPC_HASKELL_DEBUG -std=c99
 
+executable compile-proto-file
+  build-depends: base >=4.8 && <5.0
+               , async
+               , bytestring == 0.10.*
+               , containers ==0.5.*
+               , grpc-haskell
+               , optparse-generic
+               , proto3-wire
+               , protobuf-wire
+               , system-filepath
+               , text
+               , transformers
+               , turtle
+  default-language: Haskell2010
+  ghc-options:      -Wall -g -threaded -rtsopts -with-rtsopts=-N -O2
+  hs-source-dirs:   tools/compile-proto-file
+  main-is:          Main.hs
+
 executable hellos-server
   if flag(with-examples)
     build-depends:
@@ -221,4 +239,3 @@ benchmark bench
     CPP-Options: -DDEBUG
     CC-Options:  -DGRPC_HASKELL_DEBUG
   default-language: Haskell2010
-

tools/compile-proto-file/Main.hs

@@ -0,0 +1,26 @@
+{-# LANGUAGE DataKinds         #-}
+{-# LANGUAGE DeriveGeneric     #-}
+{-# LANGUAGE LambdaCase        #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeOperators     #-}
+
+import           Data.Monoid                          ((<>))
+import           Data.Protobuf.Wire.DotProto.Generate
+import           Filesystem.Path.CurrentOS            (encodeString)
+import           Options.Generic
+import           Prelude                              hiding (FilePath)
+import           Turtle                               (FilePath)
+
+data Args = Args
+  { proto :: FilePath <?> "Path to input .proto file"
+  } deriving (Generic, Show)
+instance ParseRecord Args
+
+main :: IO ()
+main = do
+  protoPath <- encodeString . unHelpful . proto <$> getRecord "Dumps a compiled .proto file to stdout"
+  readDotProtoWithContext protoPath >>= \case
+    Left err        -> fail (show err)
+    Right (dp, ctx) -> case renderHsModuleForDotProto dp ctx of
+      Left err  -> fail ("Error compiling " <> protoPath <> ": " <> show err)
+      Right src -> putStrLn src