CLJS-3010: Datafy does not properly check for whether the datafied value supports metadata

Datafy correctly detects if return value supports metadata

Author: Will Acton

src/main/cljs/clojure/datafy.cljs

@@ -21,7 +21,7 @@
   (let [v ((or (-> x meta ::datafy) -datafy) x)]
     (if (identical? v x)
       v
-      (if (object? v)
+      (if (implements? IWithMeta v)
         (vary-meta v assoc ::obj x)
         v))))
 

src/test/cljs/clojure/datafy_test.cljs

@@ -0,0 +1,24 @@
+;; Copyright (c) Rich Hickey. All rights reserved.
+;; The use and distribution terms for this software are covered by the
+;; Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
+;; which can be found in the file epl-v10.html at the root of this distribution.
+;; By using this software in any fashion, you are agreeing to be bound by
+;; the terms of this license.
+;; You must not remove this notice, or any other, from this software.
+
+(ns clojure.datafy-test
+  (:require [cljs.test :as test
+             :refer-macros [deftest is testing]]
+            [clojure.datafy :as d]))
+
+(deftest datafy-test
+  (testing "Datafy works when datafied value is arbitrary JS objects"
+    (let [datafied #js {}
+          x (with-meta [1 2 3] {:clojure.datafy/datafy (fn [_] datafied)})]
+      (is (= datafied (d/datafy x)))))
+  (testing "Datafy adds ::obj metadata when return value != original value and supports metadata"
+    (let [datafied [2 3 4]
+          original [1 2 3]
+          x (with-meta original {:clojure.datafy/datafy (fn [_] datafied)})]
+      (is (= datafied (d/datafy x)))
+      (is (= {:clojure.datafy/obj original} (meta (d/datafy x)))))))

src/test/cljs/test_runner.cljs

@@ -22,6 +22,7 @@
             [cljs.ns-test]
             [clojure.string-test]
             [clojure.data-test]
+            [clojure.datafy-test]
             [clojure.walk-test]
             [cljs.macro-test]
             [cljs.letfn-test]
@@ -67,6 +68,7 @@
   'cljs.reader-test
   'clojure.string-test
   'clojure.data-test
+  'clojure.datafy-test
   'clojure.walk-test
   'cljs.letfn-test
   'cljs.reducers-test