From 7388b50474e70cc8d4c8c0a5713a09856e4142a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Gr=C3=B6ber?= <dxld@darkboxed.org>
Date: Wed, 6 Aug 2014 20:41:59 +0200
Subject: [PATCH] Add a test making sure pattern match failures on GhcModT work
 the way I expect

---
 ghc-mod.cabal     |  1 +
 test/MonadSpec.hs | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 test/MonadSpec.hs

diff --git a/ghc-mod.cabal b/ghc-mod.cabal
index 02ae914..73922a3 100644
--- a/ghc-mod.cabal
+++ b/ghc-mod.cabal
@@ -169,6 +169,7 @@ Test-Suite spec
                         LangSpec
                         LintSpec
                         ListSpec
+                        MonadSpec
                         GhcPkgSpec
                         TestUtils
   Build-Depends:        base >= 4.0 && < 5
diff --git a/test/MonadSpec.hs b/test/MonadSpec.hs
new file mode 100644
index 0000000..7594e88
--- /dev/null
+++ b/test/MonadSpec.hs
@@ -0,0 +1,19 @@
+module MonadSpec where
+
+import Test.Hspec
+import Control.Monad.Error.Class
+import Language.Haskell.GhcMod.Types
+import Language.Haskell.GhcMod.Monad
+import Language.Haskell.GhcMod.Find
+
+spec :: Spec
+spec = do
+    describe "When using GhcModT in a do block" $
+        it "a pattern match failure causes a call to `fail` on ErrorT in the monad stack" $ do
+             (a, w)
+                 <- runGhcModT defaultOptions $
+                       do
+                         Just a <- return Nothing
+                         return "hello"
+                     `catchError` (const $ fail "oh noes")
+             a `shouldBe` (Left $ GMEString "oh noes")