From 917fc9446802f5c86f93072a070baeb8f4b73e59 Mon Sep 17 00:00:00 2001
From: Takashi AOKI <me@tak.sh>
Date: Wed, 24 Apr 2024 18:55:50 +0900
Subject: [PATCH] fix: deep-merge with nil args or values

---
 src/cljc/proton/core.cljc  | 7 ++++---
 test/proton/core_test.cljc | 8 ++++++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/cljc/proton/core.cljc b/src/cljc/proton/core.cljc
index 8db146a..94f8844 100644
--- a/src/cljc/proton/core.cljc
+++ b/src/cljc/proton/core.cljc
@@ -198,7 +198,8 @@
   "Recursively merges maps."
   [& maps]
   (letfn [(m [& xs]
-            (if (every? #(and (map? %) (not (record? %))) xs)
-              (apply merge-with m xs)
-              (last xs)))]
+            (let [xs (remove nil? xs)]
+              (if (every? #(and (map? %) (not (record? %))) xs)
+                (apply merge-with m xs)
+                (last xs))))]
     (reduce m maps)))
diff --git a/test/proton/core_test.cljc b/test/proton/core_test.cljc
index de019a2..c03a031 100644
--- a/test/proton/core_test.cljc
+++ b/test/proton/core_test.cljc
@@ -158,6 +158,14 @@
     nil 3 7))
 
 (deftest deep-merge-test
+  (is (= (core/deep-merge {:foo 1} nil)
+         {:foo 1}))
+  (is (= (core/deep-merge nil {:foo 1})
+         {:foo 1}))
+  (is (= (core/deep-merge {:foo 1} {:foo nil})
+         {:foo 1}))
+  (is (= (core/deep-merge {:foo nil} {:foo 1})
+         {:foo 1}))
   (is (= (core/deep-merge {:foo {:bar 1}} {:foo {:baz 2}})
          {:foo {:bar 1 :baz 2}}))
   (is (= (core/deep-merge {:foo {:bar 1}} {:baz 2})