Test cycle

This closes #207.

Author: super7ramp

test/clojure/core_test/cycle.cljc

@@ -0,0 +1,23 @@
+(ns clojure.core-test.cycle
+  (:require [clojure.test :refer [deftest testing are]]
+            [clojure.core-test.portability #?(:cljs :refer-macros :default :refer) [when-var-exists]]))
+
+(when-var-exists cycle
+  (deftest test-cycle
+
+    (testing "nominal cases"
+      (are [n coll expected] (= expected (take n (cycle coll)))
+                             1 nil []
+                             1 '() []
+                             1 '(1 2 3) [1]
+                             3 '(1 2 3) [1 2 3]
+                             7 '(1 2 3) [1 2 3 1 2 3 1]))
+
+    (testing "bad shape"
+      (are [coll] (thrown? #?(:cljs js/Error :default Exception) (cycle coll))
+                  :k
+                  42
+                  3.14)
+      (are [expr] (thrown? #?(:cljs js/Error :default Exception) (expr))
+                  (#'cycle)
+                  (#'cycle [] [])))))