From 993599d1cbb9ff4965d1cda4985237e77c89b46a Mon Sep 17 00:00:00 2001
From: Janpot <2109932+Janpot@users.noreply.github.com>
Date: Wed, 10 Sep 2025 15:21:41 +0200
Subject: [PATCH] [code-infra] Low-hanging ts conversion

---
 packages/mui-system/src/merge/merge.d.ts                       | 1 -
 packages/mui-system/src/merge/{merge.js => merge.ts}           | 2 +-
 .../mui-system/src/responsivePropType/responsivePropType.d.ts  | 3 ---
 .../{responsivePropType.js => responsivePropType.ts}           | 2 +-
 4 files changed, 2 insertions(+), 6 deletions(-)
 delete mode 100644 packages/mui-system/src/merge/merge.d.ts
 rename packages/mui-system/src/merge/{merge.js => merge.ts} (79%)
 delete mode 100644 packages/mui-system/src/responsivePropType/responsivePropType.d.ts
 rename packages/mui-system/src/responsivePropType/{responsivePropType.js => responsivePropType.ts} (86%)

diff --git a/packages/mui-system/src/merge/merge.d.ts b/packages/mui-system/src/merge/merge.d.ts
deleted file mode 100644
index f9df3fd9f021f5..00000000000000
--- a/packages/mui-system/src/merge/merge.d.ts
+++ /dev/null
@@ -1 +0,0 @@
-export default function merge(acc: object, item: object): object;
diff --git a/packages/mui-system/src/merge/merge.js b/packages/mui-system/src/merge/merge.ts
similarity index 79%
rename from packages/mui-system/src/merge/merge.js
rename to packages/mui-system/src/merge/merge.ts
index 8fdd03b1d17c18..ed91918dd1657c 100644
--- a/packages/mui-system/src/merge/merge.js
+++ b/packages/mui-system/src/merge/merge.ts
@@ -1,6 +1,6 @@
 import deepmerge from '@mui/utils/deepmerge';
 
-function merge(acc, item) {
+function merge(acc: object, item: object): object {
   if (!item) {
     return acc;
   }
diff --git a/packages/mui-system/src/responsivePropType/responsivePropType.d.ts b/packages/mui-system/src/responsivePropType/responsivePropType.d.ts
deleted file mode 100644
index e6d62effc86140..00000000000000
--- a/packages/mui-system/src/responsivePropType/responsivePropType.d.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-declare const responsivePropType: object;
-
-export default responsivePropType;
diff --git a/packages/mui-system/src/responsivePropType/responsivePropType.js b/packages/mui-system/src/responsivePropType/responsivePropType.ts
similarity index 86%
rename from packages/mui-system/src/responsivePropType/responsivePropType.js
rename to packages/mui-system/src/responsivePropType/responsivePropType.ts
index 5a381b0463267e..e59380f7a9dc47 100644
--- a/packages/mui-system/src/responsivePropType/responsivePropType.js
+++ b/packages/mui-system/src/responsivePropType/responsivePropType.ts
@@ -1,6 +1,6 @@
 import PropTypes from 'prop-types';
 
-const responsivePropType =
+const responsivePropType: object =
   process.env.NODE_ENV !== 'production'
     ? PropTypes.oneOfType([PropTypes.number, PropTypes.string, PropTypes.object, PropTypes.array])
     : {};