Test for Trac #2334

testsuite/tests/ghc-regress/indexed-types/should_fail/T2334.hs

+{-# LANGUAGE TypeFamilies #-}
+
+-- Trac #2334
+
+module Test where
+
+data family F r
+
+newtype instance F ()  = F () () deriving Eq
+newtype instance F Int  = H deriving Eq
+
+data instance F Bool = K1
+data instance F Bool = K2
+
+
+

testsuite/tests/ghc-regress/indexed-types/should_fail/T2334.stderr

+
+T2334.hs:9:25:
+    The constructor of a newtype must have exactly one field
+      but `F' has two
+    In the definition of data constructor `F'
+    In the newtype instance declaration for `F'
+
+T2334.hs:10:26:
+    The constructor of a newtype must have exactly one field
+      but `H' has none
+    In the definition of data constructor `H'
+    In the newtype instance declaration for `F'
+
+T2334.hs:12:14:
+    Conflicting family instance declarations:
+      data instance F Bool -- Defined at T2334.hs:12:14
+      data instance F Bool -- Defined at T2334.hs:13:14

testsuite/tests/ghc-regress/indexed-types/should_fail/all.T

@@ -26,6 +26,7 @@ test('Simple16', expect_fail, compile_fail, [''])
 test('TyFamArity1', normal, compile_fail, [''])
 test('TyFamArity2', normal, compile_fail, [''])
 test('TyFamUndec', normal, compile_fail, [''])
+test('T2334', normal, compile_fail, [''])
 
 test('GADTwrong1', if_compiler_lt('ghc', '6.9', expect_fail), compile_fail, [''])