From cee9e218ff82543e9c04841a2645d149248097af Mon Sep 17 00:00:00 2001
From: Rom Grk <romgrk.cc@gmail.com>
Date: Tue, 30 Jul 2024 10:37:08 -0400
Subject: [PATCH] fix: make theme props more stable

---
 .../src/useThemeProps/useThemeProps.js        |  4 +-
 .../src/resolveProps/resolveProps.ts          | 77 +++++++++++--------
 2 files changed, 49 insertions(+), 32 deletions(-)

diff --git a/packages/mui-system/src/useThemeProps/useThemeProps.js b/packages/mui-system/src/useThemeProps/useThemeProps.js
index d7c98f380eee85..08033ec2ca0c94 100644
--- a/packages/mui-system/src/useThemeProps/useThemeProps.js
+++ b/packages/mui-system/src/useThemeProps/useThemeProps.js
@@ -1,4 +1,5 @@
 'use client';
+import * as React from 'react';
 import getThemeProps from './getThemeProps';
 import useTheme from '../useTheme';
 
@@ -7,6 +8,5 @@ export default function useThemeProps({ props, name, defaultTheme, themeId }) {
   if (themeId) {
     theme = theme[themeId] || theme;
   }
-  const mergedProps = getThemeProps({ theme, name, props });
-  return mergedProps;
+  return React.useMemo(() => getThemeProps({ theme, name, props }), [theme, name, props]);
 }
diff --git a/packages/mui-utils/src/resolveProps/resolveProps.ts b/packages/mui-utils/src/resolveProps/resolveProps.ts
index fef2dbdb86f049..81b29f67526e34 100644
--- a/packages/mui-utils/src/resolveProps/resolveProps.ts
+++ b/packages/mui-utils/src/resolveProps/resolveProps.ts
@@ -1,8 +1,10 @@
+/* eslint-disable no-restricted-syntax */
+
 /**
  * Add keys, values of `defaultProps` that does not exist in `props`
- * @param {object} defaultProps
- * @param {object} props
- * @returns {object} resolved props
+ * @param defaultProps
+ * @param props
+ * @returns resolved props
  */
 export default function resolveProps<
   T extends {
@@ -14,36 +16,51 @@ export default function resolveProps<
 >(defaultProps: T, props: T) {
   const output = { ...props };
 
-  (Object.keys(defaultProps) as Array<keyof T>).forEach((propName) => {
-    if (propName.toString().match(/^(components|slots)$/)) {
-      output[propName] = {
-        ...(defaultProps[propName] as any),
-        ...(output[propName] as any),
-      };
-    } else if (propName.toString().match(/^(componentsProps|slotProps)$/)) {
-      const defaultSlotProps = (defaultProps[propName] || {}) as T[keyof T];
-      const slotProps = props[propName] as {} as T[keyof T];
-      output[propName] = {} as T[keyof T];
+  for (const key in defaultProps) {
+    if (Object.prototype.hasOwnProperty.call(defaultProps, key)) {
+      const propName = key as keyof T;
+
+      if (propName === 'components' || propName === 'slots') {
+        output[propName] = {
+          ...(defaultProps[propName] as any),
+          ...(output[propName] as any),
+        };
+      } else if (propName === 'componentsProps' || propName === 'slotProps') {
+        const defaultSlotProps = defaultProps[propName] as T[keyof T] | undefined;
+        const slotProps = props[propName] as {} as T[keyof T] | undefined;
+
+        if (!slotProps || isObjectEmpty(slotProps)) {
+          // Reduce the iteration if the slot props is empty
+          output[propName] = defaultSlotProps || ({} as T[keyof T]);
+        } else if (!defaultSlotProps || isObjectEmpty(defaultSlotProps)) {
+          // Reduce the iteration if the default slot props is empty
+          output[propName] = slotProps;
+        } else {
+          output[propName] = { ...slotProps };
 
-      if (!slotProps || !Object.keys(slotProps)) {
-        // Reduce the iteration if the slot props is empty
-        output[propName] = defaultSlotProps;
-      } else if (!defaultSlotProps || !Object.keys(defaultSlotProps)) {
-        // Reduce the iteration if the default slot props is empty
-        output[propName] = slotProps;
-      } else {
-        output[propName] = { ...slotProps };
-        Object.keys(defaultSlotProps).forEach((slotPropName) => {
-          (output[propName] as Record<string, unknown>)[slotPropName] = resolveProps(
-            (defaultSlotProps as Record<string, any>)[slotPropName],
-            (slotProps as Record<string, any>)[slotPropName],
-          );
-        });
+          for (const slotKey in defaultSlotProps) {
+            if (Object.prototype.hasOwnProperty.call(defaultSlotProps, slotKey)) {
+              const slotPropName = slotKey;
+              (output[propName] as Record<string, unknown>)[slotPropName] = resolveProps(
+                (defaultSlotProps as Record<string, any>)[slotPropName],
+                (slotProps as Record<string, any>)[slotPropName],
+              );
+            }
+          }
+        }
+      } else if (output[propName] === undefined) {
+        output[propName] = defaultProps[propName];
       }
-    } else if (output[propName] === undefined) {
-      output[propName] = defaultProps[propName];
     }
-  });
+  }
 
   return output;
 }
+
+function isObjectEmpty(object: Object) {
+  // eslint-disable-next-line
+  for (const _ in object) {
+    return false;
+  }
+  return true;
+}