1 files changed, 72 insertions, 0 deletions
diff --git a/stdlib/source/test/lux/world/money.lux b/stdlib/source/test/lux/world/money.lux
new file mode 100644
index 000000000..dc21b0603
--- /dev/null
+++ b/stdlib/source/test/lux/world/money.lux
@@ -0,0 +1,72 @@
+(.require
+ [library
+  [lux (.except)
+   [abstract
+    [monad (.only do)]
+    [\\specification
+     ["[0]S" equivalence]]]
+   [control
+    ["[0]" maybe (.use "[1]#[0]" functor)]]
+   [data
+    ["[0]" text (.only)
+     ["%" \\format]]]
+   [math
+    ["[0]" random (.only Random)]
+    [number
+     ["n" nat]]]
+   [test
+    ["_" property (.only Test)]]]]
+ [\\library
+  ["[0]" / (.only)
+   ["[0]" currency]]]
+ ["[0]" /
+  ["[1][0]" currency]])
+
+(def .public random
+  (Random (Ex (_ of)
+            (/.Money of)))
+  (do random.monad
+    [expected_currency /currency.random
+     expected_amount random.nat]
+    (in (/.money expected_currency expected_amount))))
+
+(def .public test
+  Test
+  (<| (_.covering /._)
+      (do [! random.monad]
+        [.let [expected_currency currency.usd]
+         expected_amount random.nat
+
+         expected_parameter (random.only (n.> 0) random.nat)
+         expected_subject random.nat])
+      (_.for [/.Money])
+      (all _.and
+           (_.for [/.equivalence]
+                  (equivalenceS.spec /.equivalence ..random))
+           
+           (_.coverage [/.money /.currency /.amount]
+             (let [it (/.money expected_currency expected_amount)]
+               (and (same? expected_currency (/.currency it))
+                    (same? expected_amount (/.amount it)))))
+           (_.coverage [/.+ /.-]
+             (let [parameter (/.money expected_currency expected_parameter)
+                   subject (/.money expected_currency expected_subject)]
+               (and (|> subject
+                        (/.+ parameter)
+                        (at /.equivalence = subject)
+                        not)
+                    (|> subject
+                        (/.+ parameter)
+                        (/.- parameter)
+                        (maybe#each (at /.equivalence = subject))
+                        (maybe.else false)))))
+           (do !
+             [it ..random]
+             (_.coverage [/.format]
+               (and (text.starts_with? (%.nat (/.amount it))
+                                       (text.replaced_once "." "" (/.format it)))
+                    (text.ends_with? (currency.alphabetic_code (/.currency it))
+                                     (/.format it)))))
+
+           /currency.test
+           )))