From 6a6e0ec683977106039b733591c14c7c3bd8c88d Mon Sep 17 00:00:00 2001
From: Vigen <47vigen@gmail.com>
Date: Sat, 30 Jul 2022 10:48:23 +0430
Subject: [PATCH 1/2] fix apply on undefined values

---
 packages/collection-diff-apply/index.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/packages/collection-diff-apply/index.js b/packages/collection-diff-apply/index.js
index c5d2c3265..0e80d63e5 100644
--- a/packages/collection-diff-apply/index.js
+++ b/packages/collection-diff-apply/index.js
@@ -118,6 +118,10 @@ function diffApply(obj, diff, pathConverter) {
       Array.isArray(subObject) ? subObject.splice(lastProp, 1) : delete subObject[lastProp];
     }
     if (thisOp === REPLACE || thisOp === ADD) {
+      if (subObject === undefined) {
+        if (typeof lastProp === "number") subObject = [];
+        else subObject = {};
+      }
       subObject[lastProp] = thisDiff.value;
     }
 

From 5ac8ef1d112df5922a2f402f223a553dd3fa1715 Mon Sep 17 00:00:00 2001
From: Vigen <47vigen@gmail.com>
Date: Sat, 30 Jul 2022 10:55:43 +0430
Subject: [PATCH 2/2] better check lastProp

---
 packages/collection-diff-apply/index.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/collection-diff-apply/index.js b/packages/collection-diff-apply/index.js
index 0e80d63e5..bee6798ae 100644
--- a/packages/collection-diff-apply/index.js
+++ b/packages/collection-diff-apply/index.js
@@ -119,8 +119,8 @@ function diffApply(obj, diff, pathConverter) {
     }
     if (thisOp === REPLACE || thisOp === ADD) {
       if (subObject === undefined) {
-        if (typeof lastProp === "number") subObject = [];
-        else subObject = {};
+        if (isNaN(lastProp)) subObject = {};
+        else subObject = [];
       }
       subObject[lastProp] = thisDiff.value;
     }