2 files changed, 28 insertions, 4 deletions

diff --git a/tests/Encoding.hs b/tests/Encoding.hs
index 0b678a25..8afd3625 100644
--- a/tests/Encoding.hs
+++ b/tests/Encoding.hs
@@ -35,7 +35,7 @@ instance Arbitrary Block where
   arbitrary = Block <$> positive <*> positive <*> arbitrary
 
 instance Arbitrary Bitfield where
-  arbitrary = mkBitfield <$> positive <*> arbitrary
+  arbitrary = mkBitfield <$> (succ <$> positive) <*> arbitrary
 
 instance Arbitrary PortNumber where
   arbitrary = fromIntegral <$> (arbitrary :: Gen Word16)
diff --git a/tests/Main.hs b/tests/Main.hs
index bc3f7809..ef4ab8a7 100644
--- a/tests/Main.hs
+++ b/tests/Main.hs
@@ -1,14 +1,38 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Main (main) where
 
+import Control.Applicative
+import Data.IntervalSet
+import Data.List as L
+import Data.Ord
 import Data.Word
+
 import Test.Framework (defaultMain)
 import Test.Framework.Providers.QuickCheck2 (testProperty)
+import Test.QuickCheck
+
+import Data.Bitfield as BF
+import Network.BitTorrent as BT
 
 import Encoding
 
-import Data.Bitfield as BT
-import Network.BitTorrent as BT
+
+
+instance Arbitrary IntSet where
+  arbitrary = fromList <$> arbitrary
+
+prop_completenessRange :: Bitfield -> Bool
+prop_completenessRange bf = 0 <= c && c <= 1
+  where
+    c = completeness bf
+
+prop_rarestInRange :: [Bitfield] -> Bool
+prop_rarestInRange xs = case rarest xs of
+  Just r  -> 0 <= r && r < totalCount (maximumBy (comparing totalCount) xs)
+  Nothing -> True
 
 main :: IO ()
-main = defaultMain []
+main = defaultMain
+  [ testProperty "completeness range" prop_completenessRange
+  , testProperty "rarest in range"    prop_rarestInRange
+  ]