Use ghc-options in HPack

snack-lib/hpack.nix

@@ -34,6 +34,7 @@ in
         mkDeps = obj: dropVersionBounds (optAttr obj "dependencies" []);
         topDeps = mkDeps package;
         topExtensions = optAttr package "default-extensions" [];
+        topGhcOpts = optAttr package "ghc-options" [];
         packageLib = withAttr package "library" null (component:
             { src =
                 let
@@ -48,6 +49,7 @@ in
                     builtins.toPath "${builtins.toString base}/${source-dirs}";
               dependencies = topDeps ++ mkDeps component;
               extensions = topExtensions ++ (optAttr component "extensions" []);
+              ghcOpts = topGhcOpts ++ (optAttr component "ghc-options" []);
             }
           );
 
@@ -76,7 +78,8 @@ in
                     builtins.toPath "${builtins.toString base}/${source-dirs}";
               dependencies = topDeps ++ dropVersionBounds depOrPack.wrong;
               extensions = topExtensions ++ (optAttr component "extensions" []);
-            packages = map (_: packageLib) depOrPack.right;
+              ghcOpts = topGhcOpts ++ (optAttr component "ghc-options" []);
+              packages = map (_: packageLib) depOrPack.right;
             };
     in
       { library = packageLib;

tests/ghc-options/Main.hs

@@ -0,0 +1,5 @@
+module Main where
+
+import Data.Text
+
+main = putStrLn $ unpack "hello"

tests/ghc-options/golden

@@ -0,0 +1 @@
+hello

tests/ghc-options/package.nix

@@ -0,0 +1,5 @@
+{ main = "Main";
+  src = ./.;
+  dependencies = [ "text" ];
+  ghcOpts = ["-XOverloadedStrings"];
+}

tests/ghc-options/package.yaml

@@ -0,0 +1,9 @@
+name: snack-extensions-test
+
+ghc-options:
+    - -XOverloadedStrings
+dependencies:
+    - text
+executable:
+    main: Main.hs
+    source-dirs: .

tests/ghc-options/test

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# vim: ft=sh sw=2 et
+
+set -euo pipefail
+
+test() {
+  $SNACK build
+  $SNACK run | diff golden -
+
+  TMP_FILE=$(mktemp)
+
+  capture_io "$TMP_FILE" main | $SNACK ghci
+
+  diff golden $TMP_FILE
+  rm $TMP_FILE
+}
+
+SNACK="snack --package-file ./package.nix" test
+SNACK="snack --package-file ./package.nix -l ../../snack-lib" test
+SNACK="snack --package-file ./package.yaml" test