From d9c29490e3187f0d6d3bf588edc6f2dd8fe3314a Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Wed, 10 Jun 2026 13:46:06 +0100
Subject: [PATCH] Support --shadow-file with --native-parser

---
 mypy/build.py               |  4 +++-
 test-data/unit/cmdline.test | 29 +++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/mypy/build.py b/mypy/build.py
index 97db8fe1646cd..7fc9526ccb2fe 100644
--- a/mypy/build.py
+++ b/mypy/build.py
@@ -1030,7 +1030,9 @@ def parse_all(self, states: list[State], post_parse: bool = True) -> None:
 
         parallel_states = []
         for state in states:
-            if not self.fscache.exists(state.xpath, real_only=True):
+            if not self.fscache.exists(state.xpath, real_only=True) or (
+                self.shadow_map and self.maybe_swap_for_shadow_path(state.xpath) != state.xpath
+            ):
                 state.source = state.get_source()
             if state.tree is not None:
                 # The file was already parsed.
diff --git a/test-data/unit/cmdline.test b/test-data/unit/cmdline.test
index cfba7a81e9285..60b42d115284f 100644
--- a/test-data/unit/cmdline.test
+++ b/test-data/unit/cmdline.test
@@ -530,6 +530,35 @@ variable has type "bytes")
     b: bytes = 1
                ^
 
+[case testShadowFileWithNativeParser]
+# cmd: mypy --native-parser --shadow-file source.py shadow.py source.py
+[file source.py]
+x: int = 1
+reveal_type(x)
+[file shadow.py]
+x: str = "y"
+reveal_type(x)
+[out]
+source.py:2: note: Revealed type is "str"
+== Return code: 0
+
+[case testShadowFileWithNativeParserParallel]
+# cmd: mypy --native-parser --shadow-file a.py a_shadow.py main.py a.py b.py
+[file main.py]
+import a
+import b
+[file a.py]
+x: int = 1
+reveal_type(x)
+[file b.py]
+y: int = 2
+[file a_shadow.py]
+x: str = "y"
+reveal_type(x)
+[out]
+a.py:2: note: Revealed type is "str"
+== Return code: 0
+
 [case testConfigWarnUnusedSection1]
 # cmd: mypy foo.py quux.py spam/eggs.py
 [file mypy.ini]