From 0d36ce5eb8d00a9e6691bdf3f7bf2307ae5231a7 Mon Sep 17 00:00:00 2001
From: Solo-steven <ssteven19@kimo.com>
Date: Tue, 21 Mar 2023 17:26:27 +0800
Subject: [PATCH] fix: Do not overwrite the null value, skip it for deepMerge
 case.

---
 packages/utils/src/eslint-utils/applyDefault.ts | 2 +-
 packages/utils/src/eslint-utils/deepMerge.ts    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/utils/src/eslint-utils/applyDefault.ts b/packages/utils/src/eslint-utils/applyDefault.ts
index 1c96ffec769..0f28cfa7d7d 100644
--- a/packages/utils/src/eslint-utils/applyDefault.ts
+++ b/packages/utils/src/eslint-utils/applyDefault.ts
@@ -26,7 +26,7 @@ function applyDefault<TUser extends readonly unknown[], TDefault extends TUser>(
     if (userOptions[i] !== undefined) {
       const userOpt = userOptions[i];
       if (isObjectNotArray(userOpt) && isObjectNotArray(opt)) {
-        options[i] = deepMerge(opt || {}, userOpt);
+        options[i] = deepMerge(opt, userOpt);
       } else {
         options[i] = userOpt;
       }
diff --git a/packages/utils/src/eslint-utils/deepMerge.ts b/packages/utils/src/eslint-utils/deepMerge.ts
index 9b7baee5ebb..78c2920d8d0 100644
--- a/packages/utils/src/eslint-utils/deepMerge.ts
+++ b/packages/utils/src/eslint-utils/deepMerge.ts
@@ -8,7 +8,7 @@ type ObjectLike<T = unknown> = Record<string, T>;
 function isObjectNotArray<T extends ObjectLike>(
   obj: unknown | unknown[],
 ): obj is T {
-  return typeof obj === 'object' && !Array.isArray(obj);
+  return typeof obj === 'object' && obj != null && !Array.isArray(obj);
 }
 
 /**