Add testcase for #816

2 files changed, 15 insertions, 0 deletions

diff --git a/testsuite/tests/typecheck/should_compile/T816.hs b/testsuite/tests/typecheck/should_compile/T816.hs
new file mode 100644
index 0000000000..4c319ea5be
--- /dev/null
+++ b/testsuite/tests/typecheck/should_compile/T816.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE FunctionalDependencies #-}
+{-# LANGUAGE UndecidableInstances #-}
+
+module T816 where
+
+class Foo x y | x -> y where
+  foo :: x -> y
+
+class Bar x y where
+  bar :: x -> y -> Int
+
+instance (Foo x y, Bar y z) => Bar x z where
+  bar x z = bar (foo x) z
diff --git a/testsuite/tests/typecheck/should_compile/all.T b/testsuite/tests/typecheck/should_compile/all.T
index 060d179400..faac5bba9f 100644
--- a/testsuite/tests/typecheck/should_compile/all.T
+++ b/testsuite/tests/typecheck/should_compile/all.T
@@ -266,6 +266,7 @@ test('FD3', normal, compile_fail, [''])
 test('FD4', normal, compile, [''])
 
 test('faxen', normal, compile, [''])
+test('T816', normal, compile, [''])
 test('T1495', normal, compile, [''])
 test('T2045', normal, compile, [''])   # Needs -fhpc
 test('T2478', normal, compile, [''])