Add assoc-in-some function

Author: erikcc02

src/medley/core.cljc

@@ -53,6 +53,11 @@
          m
          (persistent! acc))))))
 
+(defn assoc-in-some
+  "Associates a value v in a nested associative structure provided that v is not nil."
+  [m k v]
+  (cond-> m (some? v) (assoc-in k v)))
+
 (defn update-existing
   "Updates a value in a map given a key and a function, if and only if the key
   exists in the map. See: `clojure.core/update`."

test/medley/core_test.cljc

@@ -33,6 +33,14 @@
   (is (nil? (m/assoc-some nil :a nil)))
   (is (nil? (m/assoc-some nil :a nil :b nil))))
 
+(deftest test-assoc-in-some
+  (is (= (m/assoc-in-some {:a 1 :b {:c 2}} [:b] 3) {:a 1 :b 3}))
+  (is (= (m/assoc-in-some [{:a 1} {:a 2}] [1 :a] 3) [{:a 1} {:a 3}]))
+  (is (= (m/assoc-in-some [{:a 1} {:a 2}] [1 :a] false) [{:a 1} {:a false}]))
+  (is (= (m/assoc-in-some [{:a 1} {:a 2}] [1 :a] nil) [{:a 1} {:a 2}]))
+  (is (nil? (m/assoc-in-some nil :a nil)))
+  (is (nil? (m/assoc-in-some nil [:a :b] nil))))
+
 (deftest test-update-existing
   (is (= (m/update-existing {:a 1} :a inc) {:a 2}))
   (is (= (m/update-existing {:a 1 :b 2} :a inc) {:a 2 :b 2}))