fix(test): test for applyMetas handles duplicate keys in correct order now

test/PandocSpec.hs

@@ -19,10 +19,10 @@ import Text.Pandoc.Arbitrary ()
 
 -- Instance Arbitrary Meta is somewhat useless, as it always generates the same 3 keys.
 newtype ArbitraryMeta = ArbitraryMeta { unArbitraryMeta :: Meta }
-  deriving newtype (Eq, Ord, Semigroup, Monoid, Show, Read)
+  deriving newtype (Eq, Ord, Semigroup, Monoid, Show, Read, Typeable)
 
 newtype ArbitraryPandoc = ArbitraryPandoc { unArbitraryPandoc :: Pandoc }
-  deriving newtype (Eq, Ord, Show, Read)
+  deriving newtype (Eq, Ord, Show, Read, Typeable)
 
 newtype ArbitraryMapText a = ArbitraryMapText { unArbitraryMapText :: [(Text, a)] }
 
@@ -75,9 +75,8 @@ spec = do
         metaList1 :: [(Text, Maybe MetaValue)] = second (Just . MetaString) <$> unArbitraryMapText metaList0
         pd = unArbitraryPandoc apd
         (Pandoc metaNew _) = applyMetas metaList1 pd
-        metaMap1 = Map.fromList metaList1 -- remove duplicate keys
-        keys1 = Map.keysSet metaMap1
-        metaList' = [(k, Just t) | (k, t) <- mlist metaNew, k `Set.member` keys1]
+        metaMap1 = Map.fromList $ reverse metaList1 -- remove duplicate keys, keeping the first        
+        metaList' = [(k, Just t) | (k, t) <- mlist metaNew, k `Set.member` metaMap1]
       metaList' `shouldMatchList` Map.toAscList metaMap1
 
     it "should preserve untouched settings" $ do