From 8abab1c2ff8d76de038f54f95a337dd2e4354958 Mon Sep 17 00:00:00 2001
From: David Chambers <dc@davidchambers.me>
Date: Sat, 21 Jan 2017 14:05:45 +0100
Subject: [PATCH] test all four Nothing/Just permutations for S.ap

---
 test/ap.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/test/ap.js b/test/ap.js
index 5f8ef148..73d04cef 100644
--- a/test/ap.js
+++ b/test/ap.js
@@ -16,6 +16,9 @@ test('ap', function() {
   eq(S.ap([S.inc], []), []);
   eq(S.ap([S.inc], [1, 2, 3]), [2, 3, 4]);
   eq(S.ap([S.dec, Math.sqrt], [1, 4, 9]), [0, 3, 8, 1, 2, 3]);
-  eq(S.ap(S.Just(S.inc), S.Just(42)), S.Just(43));
+  eq(S.ap(S.Nothing, S.Nothing), S.Nothing);
+  eq(S.ap(S.Nothing, S.Just(9)), S.Nothing);
+  eq(S.ap(S.Just(Math.sqrt), S.Nothing), S.Nothing);
+  eq(S.ap(S.Just(Math.sqrt), S.Just(9)), S.Just(3));
 
 });