2 files changed, 87 insertions, 0 deletions
diff --git a/stdlib/test/test/lux/time.lux b/stdlib/test/test/lux/time.lux
new file mode 100644
index 000000000..becdfc068
--- /dev/null
+++ b/stdlib/test/test/lux/time.lux
@@ -0,0 +1,86 @@
+(;module:
+  lux
+  (lux [io]
+       (control [monad #+ do Monad]
+                pipe)
+       (data [text]
+             text/format
+             ["R" result]
+             [number "Int/" Number<Int>])
+       (math ["r" random])
+       ["@" time])
+  lux/test)
+
+(def: (limited-int size)
+  (-> Nat (r;Random Int))
+  (do r;Monad<Random>
+    [sample r;int]
+    (wrap (|> sample
+              Int/abs
+              (i.% (nat-to-int size))
+              (i.* (Int/signum sample))))))
+
+(def: (pow exp base)
+  (-> Nat Int Int)
+  (case exp
+    +0 1
+    _ (loop [exp exp
+             result base]
+        (case exp
+          +1 result
+          _ (recur (n.dec exp)
+                   (i.* base result))))))
+(def: boundary Int (|> 2 (pow +31) (i.* @;second)))
+
+(def: time (r;Random @;Time)
+  (|> r;int
+      (r;filter (i.>= 0))
+      ## (:: r;Monad<Random> map (i.% boundary))
+      ))
+
+(context: "Equality"
+  [sample time
+   #let [(^open) @;Eq<Time>]]
+  (test "Every time equals itself."
+        (= sample sample)))
+
+(context: "Arithmetic"
+  [subject time
+   param time]
+  ($_ seq
+      (test "Can add and subtract times."
+            (and (|> subject (@;t.+ param) (@;t.- param) (@;t.= subject))
+                 (|> subject (@;t.- param) (@;t.+ param) (@;t.= subject))))
+      (test "Subtracting a time from itself results in the epoch."
+            (@;t.= @;epoch
+                   (@;t.- subject subject)))
+      ))
+
+(context: "Order"
+  [reference time
+   sample time
+   #let [(^open) @;Order<Time>]]
+  (test "Can compare times."
+        (and (or (< reference sample)
+                 (>= reference sample))
+             (or (> reference sample)
+                 (<= reference sample))))
+  )
+
+(context: "Codec"
+  ## #seed +1484609979608
+  ## #seed +1484654273059
+  [sample time
+   ## #let [sample 1095292800_000]
+   ## #let [_ (log! (format "sample = " (%i sample)))]
+   #let [(^open "&/") @;Codec<Text,Time>]]
+  (test "Can encode/decode times."
+        (|> sample
+            &/encode
+            &/decode
+            (case> (#R;Success decoded)
+                   (@;t.= sample decoded)
+
+                   (#R;Error error)
+                   false)))
+  )
diff --git a/stdlib/test/tests.lux b/stdlib/test/tests.lux
index 34c5c9be2..ba0da53f8 100644
--- a/stdlib/test/tests.lux
+++ b/stdlib/test/tests.lux
@@ -9,6 +9,7 @@
         (lux ["_;" cli]
              ["_;" host]
              ["_;" io]
+             ["_;" time]
              (concurrency ["_;" actor]
                           ["_;" atom]
                           ["_;" frp]