From 70ad4d6d9b330e8dc780e53470e261cb096fd5fc Mon Sep 17 00:00:00 2001
From: Adam Dangoor <adamdangoor@gmail.com>
Date: Wed, 24 Jan 2024 12:48:59 +0000
Subject: [PATCH] Use more precise type for formparser.MultiPartParser.parse
 return

Without this change, `pyright` with `typeCheckingMode` set to `strict` reports:

```
error: Type of "fields" is partially unknown
    Type of "fields" is "MultiDict[Unknown, Unknown]" (reportUnknownVariableType)
```

when I use this method.
---
 CHANGES.rst                | 8 ++++++++
 src/werkzeug/formparser.py | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index 186e8f580..b23bffcd4 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,5 +1,13 @@
 .. currentmodule:: werkzeug
 
+Version 3.0.2
+-------------
+
+Unreleased
+
+-   Make the return type of ``MultiPartParser.parse`` more
+    precise. :issue:`2840`
+
 Version 3.0.1
 -------------
 
diff --git a/src/werkzeug/formparser.py b/src/werkzeug/formparser.py
index ee30666dd..5117a2673 100644
--- a/src/werkzeug/formparser.py
+++ b/src/werkzeug/formparser.py
@@ -352,7 +352,7 @@ def start_file_streaming(
 
     def parse(
         self, stream: t.IO[bytes], boundary: bytes, content_length: int | None
-    ) -> tuple[MultiDict, MultiDict]:
+    ) -> tuple[MultiDict[str, str], MultiDict[str, FileStorage]]:
         current_part: Field | File
         container: t.IO[bytes] | list[bytes]
         _write: t.Callable[[bytes], t.Any]