Test Trac #8470

2 files changed, 12 insertions, 0 deletions

diff --git a/testsuite/tests/deSugar/should_compile/T8470.hs b/testsuite/tests/deSugar/should_compile/T8470.hs
new file mode 100644
index 0000000000..8784c589ac
--- /dev/null
+++ b/testsuite/tests/deSugar/should_compile/T8470.hs
@@ -0,0 +1,11 @@
+{-# LANGUAGE TypeFamilies #-}
+{-# OPTIONS_GHC -fwarn-unused-do-bind #-}
+module T8470 where
+
+data User
+type family MethodResult ev
+type instance MethodResult User = ()
+type EventResult a = MethodResult a
+
+foo = do undefined :: IO (EventResult User)
+         return ()
diff --git a/testsuite/tests/deSugar/should_compile/all.T b/testsuite/tests/deSugar/should_compile/all.T
index 4551709e65..ac748d3ae4 100644
--- a/testsuite/tests/deSugar/should_compile/all.T
+++ b/testsuite/tests/deSugar/should_compile/all.T
@@ -102,3 +102,4 @@ test('T5252Take2',
      ['$MAKE -s --no-print-directory T5252Take2'])
 test('T2431', normal, compile, ['-ddump-simpl -dsuppress-uniques'])
 test('T7669', normal, compile, [''])
+test('T8470', normal, compile, [''])