add tests for collection operations, improve error message for 'nth'.

xsc · Oct 3, 2017 · e6d5c55 · e6d5c55
1 parent f653eb6
commit e6d5c55
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Showing 2 changed files with 49 additions and 1 deletion.
diff --git a/src/claro/data/ops/collections.cljc b/src/claro/data/ops/collections.cljc
@@ -64,7 +64,19 @@
     p/every-processable?
     (wrap-assert-coll
       (fn [[v n]]
-        (core/nth v n))
+        (try
+          (core/nth v n)
+          (catch java.lang.IndexOutOfBoundsException e
+            (throw
+              (IllegalArgumentException.
+                (format
+                  (str "index %d out of bounds when calling 'nth'.%n"
+                       "resolvable: %s%n"
+                       "collection: %s")
+                  n
+                  (pr-str value)
+                  (pr-str v))
+                e)))))
       sequential?
       "can only apply 'nth' to sequentials, given:")))
 

diff --git a/test/claro/data/ops/collections_test.clj b/test/claro/data/ops/collections_test.clj
@@ -45,3 +45,39 @@
       [{nums1 :nums, r1 :resolvable} gen-collection
        {nums2 :nums, r2 :resolvable} gen-collection]
       (= (map + nums1 nums2) (run!! (ops/map + r1 r2))))))
+
+(defspec t-first (test/times 50)
+  (let [run!! (comp deref (make-engine))]
+    (prop/for-all
+      [{:keys [nums resolvable]} gen-collection]
+      (= (first nums) (run!! (ops/first resolvable))))))
+
+(defspec t-nth (test/times 50)
+  (let [run!! (comp deref (make-engine))]
+    (prop/for-all
+      [{:keys [nums resolvable]} gen-collection
+       n       gen/pos-int
+       wrapper (gen/elements [identity ->Identity])]
+      (let [value (ops/nth resolvable (wrapper n))]
+        (if (< n (count nums))
+          (= (nth nums n) (run!! value))
+          (boolean
+            (is
+              (thrown-with-msg?
+                java.lang.IllegalArgumentException
+                #"index \d+ out of bounds when calling 'nth'"
+                (run!! value)))))))))
+
+(defspec t-take (test/times 50)
+  (let [run!! (comp deref (make-engine))]
+    (prop/for-all
+      [{:keys [nums resolvable]} gen-collection
+       n gen/pos-int]
+      (= (take n nums) (run!! (ops/take n resolvable))))))
+
+(defspec t-drop (test/times 50)
+  (let [run!! (comp deref (make-engine))]
+    (prop/for-all
+      [{:keys [nums resolvable]} gen-collection
+       n gen/pos-int]
+      (= (drop n nums) (run!! (ops/drop n resolvable))))))