Fix the case when result of map-lookup is falsy (xapix-io#114)

* Fix the case when result of map-lookup is falsy

* Add test

Author: DeLaGuardo

src/axel_f/compiler.cljc

@@ -24,9 +24,12 @@
   (reduce
    (fn [_ x]
      (when (map? x)
-       (when-let [v (or (get x idx)
-                        (get x (switch-type idx)))]
-         (reduced v))))
+       (let [idx' (switch-type idx)]
+         (cond
+           (and (contains? x idx) (some? (get x idx)))
+           (reduced (get x idx))
+           (and (contains? x idx') (some? (get x idx')))
+           (reduced (get x idx'))))))
    nil ctxs))
 
 (defn lookup [ctx [p & path]]

test/axel_f/reference_test.cljc

@@ -69,3 +69,9 @@
 (t/deftest reference-can-start-with-number
   (t/is (= 1
            ((af/compile "1to1.foo") {"1to1" {:foo 1}}))))
+
+(t/deftest falsy-values
+  (t/is (= [false true 1]
+           ((af/compile "foo.[].bar") {"foo" [{:bar false}
+                                              {"bar" true}
+                                              {"bar" 1}]}))))