[commit: testsuite] wip/T8503: Testcase for Coercible and newtype families (#8548) (8880e67)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/testsuite

On branch  : wip/T8503
Link       : http://ghc.haskell.org/trac/ghc/changeset/8880e67fb25f4953c7c2413f16e79ddcf4a7d0e7/testsuite

>---------------------------------------------------------------

commit 8880e67fb25f4953c7c2413f16e79ddcf4a7d0e7
Author: Joachim Breitner <mail at joachim-breitner.de>
Date:   Fri Nov 22 10:21:36 2013 +0000

    Testcase for Coercible and newtype families (#8548)


>---------------------------------------------------------------

8880e67fb25f4953c7c2413f16e79ddcf4a7d0e7
 tests/typecheck/should_run/TcCoercible.hs     |    9 ++++++++-
 tests/typecheck/should_run/TcCoercible.stdout |    2 ++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/tests/typecheck/should_run/TcCoercible.hs b/tests/typecheck/should_run/TcCoercible.hs
index 855a133..e3b29af 100644
--- a/tests/typecheck/should_run/TcCoercible.hs
+++ b/tests/typecheck/should_run/TcCoercible.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE RoleAnnotations, StandaloneDeriving, FlexibleContexts, UndecidableInstances, GADTs #-}
+{-# LANGUAGE RoleAnnotations, StandaloneDeriving, FlexibleContexts, UndecidableInstances, GADTs, TypeFamilies #-}
 
 import GHC.Prim (Coercible, coerce)
 import Data.Monoid (mempty, First(First), Last())
@@ -31,6 +31,10 @@ data Oracle where Oracle :: Coercible (Fix (Either Age)) (Fix  (Either Int)) =>
 foo :: Oracle -> Either Age (Fix (Either Age)) -> Fix (Either Int)
 foo Oracle = coerce
 
+-- This ensures that Coercible looks into newtype instances (#8548)
+data family Fam k
+newtype instance Fam Int = FamInt Bool deriving Show
+
 main = do
     print (coerce $ one                       :: Age)
     print (coerce $ age                       :: Int)
@@ -58,6 +62,9 @@ main = do
     print (coerce $ (FixEither (Left age) :: FixEither Age) :: Either Int (FixEither Int))
     print (coerce $ (Left one :: Either Int (FixEither Age)) :: FixEither Age)
 
+    print (coerce $ True :: Fam Int)
+    print (coerce $ FamInt True :: Bool)
+
     foo `seq` return ()
 
 
diff --git a/tests/typecheck/should_run/TcCoercible.stdout b/tests/typecheck/should_run/TcCoercible.stdout
index 7e06734..7b8071f 100644
--- a/tests/typecheck/should_run/TcCoercible.stdout
+++ b/tests/typecheck/should_run/TcCoercible.stdout
@@ -16,3 +16,5 @@ Left ()
 Fix (Left ())
 Left 1
 FixEither (Left (Age 1))
+FamInt True
+True