From a23ed449c784cdf81501c696bec10b1fbaeefc5f Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Fri, 14 May 2010 01:59:06 -0400
Subject: [PATCH] Added the prop_contains_proper_intransitive QuickCheck
 property, and fixed the definition of contains_proper when it found a bug.

---
 src/Cidr.hs       | 14 ++++++++++++--
 test/TestSuite.hs |  6 ++++--
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/Cidr.hs b/src/Cidr.hs
index 5c9fefd..94de123 100644
--- a/src/Cidr.hs
+++ b/src/Cidr.hs
@@ -3,7 +3,10 @@ module Cidr
   cidr_from_string,
   cidr_tests,
   combine_all,
-  prop_all_cidrs_contain_themselves
+  contains,
+  contains_proper,
+  prop_all_cidrs_contain_themselves,
+  prop_contains_proper_intransitive
 ) where
 
 import Data.List (nubBy)
@@ -124,7 +127,7 @@ contains (Cidr addr1 mbits1) (Cidr addr2 mbits2)
 
 contains_proper :: Cidr -> Cidr -> Bool
 contains_proper cidr1 cidr2 =
-    (cidr1 `contains` cidr2) && (not (cidr1 == cidr2))
+    (cidr1 `contains` cidr2) && (not (cidr2 `contains` cidr1))
 
 
 -- A CIDR range is redundant (with respect to the given list) if
@@ -296,3 +299,10 @@ cidr_tests = [ test_equality1,
 prop_all_cidrs_contain_themselves :: Cidr -> Bool
 prop_all_cidrs_contain_themselves cidr1 = cidr1 `contains` cidr1
 
+
+-- If cidr1 properly contains cidr2, then by definition cidr2
+-- does not properly contain cidr1.
+prop_contains_proper_intransitive :: Cidr -> Cidr -> Property
+prop_contains_proper_intransitive cidr1 cidr2 =
+    (cidr1 `contains_proper` cidr2) ==>
+      (not (cidr2 `contains_proper` cidr1))
diff --git a/test/TestSuite.hs b/test/TestSuite.hs
index 3538d21..4450f1d 100644
--- a/test/TestSuite.hs
+++ b/test/TestSuite.hs
@@ -2,7 +2,8 @@ import Test.HUnit
 import Test.QuickCheck.Batch
 
 import Cidr (cidr_tests,
-             prop_all_cidrs_contain_themselves)
+             prop_all_cidrs_contain_themselves,
+             prop_contains_proper_intransitive)
 
 import IPv4Address (ipv4address_tests)
 import Maskable (maskable_tests)
@@ -29,4 +30,5 @@ main = do
 
   putStrLn "QuickCheck"
   putStrLn "----------"
-  runTests "Cidr" options [ run prop_all_cidrs_contain_themselves ]
+  runTests "Cidr" options [ run prop_all_cidrs_contain_themselves,
+                            run prop_contains_proper_intransitive]
-- 
2.43.2