1 files changed, 39 insertions, 0 deletions
diff --git a/stdlib/source/test/lux/abstract/hash.lux b/stdlib/source/test/lux/abstract/hash.lux
new file mode 100644
index 000000000..c527fb9c9
--- /dev/null
+++ b/stdlib/source/test/lux/abstract/hash.lux
@@ -0,0 +1,39 @@
+(.module:
+  [lux #*
+   ["_" test (#+ Test)]
+   [abstract
+    [monad (#+ do)]
+    {[0 #spec]
+     [/
+      [functor
+       ["$." contravariant]]]}]
+   [data
+    ["." bit ("#\." equivalence)]]
+   [math
+    ["." random]
+    [number
+     ["." nat]]]]
+  {1
+   ["." / (#+ Hash)
+    [//
+     [equivalence (#+ Equivalence)]]]})
+
+(def: #export test
+  Test
+  (do random.monad
+    [leftN random.nat
+     rightN random.nat
+     #let [hash (: (Equivalence (/.Hash Nat))
+                   (structure
+                    (def: (= (^open "left\.") (^open "right\."))
+                      (and (bit\= (left\= (left\hash leftN) (left\hash leftN))
+                                  (right\= (right\hash leftN) (right\hash leftN)))
+                           (bit\= (left\= (left\hash rightN) (left\hash rightN))
+                                  (right\= (right\hash rightN) (right\hash rightN)))
+                           (bit\= (left\= (left\hash leftN) (left\hash rightN))
+                                  (right\= (right\hash leftN) (right\hash rightN)))))))]]
+    (<| (_.covering /._)
+        ($_ _.and
+            (_.for [/.functor]
+                   ($contravariant.spec hash nat.hash /.functor))
+            ))))