test for Flag.

ghc-mod.cabal

@@ -67,6 +67,7 @@ Test-Suite spec
   Hs-Source-Dirs:       test, .
   Type:                 exitcode-stdio-1.0
   Other-Modules:        Expectation
+                        FlagSpec
                         LangSpec
                         ListSpec
   Build-Depends:        base >= 4.0 && < 5

test/FlagSpec.hs

@@ -0,0 +1,14 @@
+module FlagSpec where
+
+import Control.Applicative
+import Test.Hspec
+import Expectation
+import Flag
+import Types
+
+spec :: Spec
+spec = do
+    describe "listFlags" $ do
+        it "lists up GHC flags" $ do
+            flags <- lines <$> listFlags defaultOptions
+            flags `shouldContain` "-fno-warn-orphans"