From 4e08f5c1b3aa6f0a133d1d88165946c8c3bae89d Mon Sep 17 00:00:00 2001
From: "Johnny.H" <jnhyperion@gmail.com>
Date: Thu, 13 Mar 2025 15:04:27 +0800
Subject: [PATCH 1/4] fix https://github.com/pytest-dev/pytest/issues/13292

---
 src/_pytest/assertion/rewrite.py |  4 ++--
 testing/test_assertrewrite.py    | 24 +++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/_pytest/assertion/rewrite.py b/src/_pytest/assertion/rewrite.py
index 2e606d1903a..c4f86300bd1 100644
--- a/src/_pytest/assertion/rewrite.py
+++ b/src/_pytest/assertion/rewrite.py
@@ -317,7 +317,7 @@ def _write_pyc_fp(
     flags = b"\x00\x00\x00\x00"
     fp.write(flags)
     # as of now, bytecode header expects 32-bit numbers for size and mtime (#4903)
-    mtime = int(source_stat.st_mtime) & 0xFFFFFFFF
+    mtime = source_stat.st_mtime_ns & 0xFFFFFFFF
     size = source_stat.st_size & 0xFFFFFFFF
     # "<LL" stands for 2 unsigned longs, little-endian.
     fp.write(struct.pack("<LL", mtime, size))
@@ -374,7 +374,7 @@ def _read_pyc(
     with fp:
         try:
             stat_result = os.stat(source)
-            mtime = int(stat_result.st_mtime)
+            mtime = stat_result.st_mtime_ns
             size = stat_result.st_size
             data = fp.read(16)
         except OSError as e:
diff --git a/testing/test_assertrewrite.py b/testing/test_assertrewrite.py
index 02d1c3e52ff..c072902328d 100644
--- a/testing/test_assertrewrite.py
+++ b/testing/test_assertrewrite.py
@@ -1383,7 +1383,7 @@ def test_read_pyc_more_invalid(self, tmp_path: Path) -> None:
 
         mtime = b"\x58\x3c\xb0\x5f"
         mtime_int = int.from_bytes(mtime, "little")
-        os.utime(source, (mtime_int, mtime_int))
+        os.utime(source, ns=(mtime_int, mtime_int))
 
         size = len(source_bytes).to_bytes(4, "little")
 
@@ -2374,3 +2374,25 @@ def test_saferepr_unbounded(self):
             _saferepr(self.Help)
             == f"<class '{Path(__file__).stem}.{self.__class__.__name__}.Help'>"
         )
+
+
+class TestIssue13292:
+    def test_load_cache_based_on_file_st_mtime_ns(self, pytester: Pytester) -> None:
+        pytester.makepyfile("""
+            def test_dummy1():
+                def func():
+                    pass
+                print(func.__qualname__)
+            """)
+        r = pytester.runpytest("-s")
+        assert r.ret == 0
+        assert "test_dummy1.<locals>.func" in r.stdout.str()
+        pytester.makepyfile("""
+            def test_dummy2():
+                def func():
+                    pass
+                print(func.__qualname__)
+            """)
+        r = pytester.runpytest("-s")
+        assert r.ret == 0
+        assert "test_dummy2.<locals>.func" in r.stdout.str()

From e4d70c72726754e9639a7ce61017b789cd28e925 Mon Sep 17 00:00:00 2001
From: "Johnny.H" <jnhyperion@gmail.com>
Date: Thu, 13 Mar 2025 15:08:39 +0800
Subject: [PATCH 2/4] fix https://github.com/pytest-dev/pytest/issues/13292

---
 AUTHORS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/AUTHORS b/AUTHORS
index 95e6b13f11e..731f912178b 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -488,3 +488,4 @@ Zachary OBrien
 Zhouxin Qiu
 Zoltán Máté
 Zsolt Cserna
+Johnny Huang

From c573aa4e9932c213bfac3adf428afe7ac3fa7aa3 Mon Sep 17 00:00:00 2001
From: "Johnny.H" <jnhyperion@gmail.com>
Date: Fri, 14 Mar 2025 10:33:21 +0800
Subject: [PATCH 3/4] Add changelog

---
 changelog/13292.bugfix.rst    | 1 +
 testing/test_assertrewrite.py | 7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 changelog/13292.bugfix.rst

diff --git a/changelog/13292.bugfix.rst b/changelog/13292.bugfix.rst
new file mode 100644
index 00000000000..c60cfd53ac9
--- /dev/null
+++ b/changelog/13292.bugfix.rst
@@ -0,0 +1 @@
+Fixed stale pyc cache loading after rapid test file updates.
diff --git a/testing/test_assertrewrite.py b/testing/test_assertrewrite.py
index c072902328d..c19181cbeb3 100644
--- a/testing/test_assertrewrite.py
+++ b/testing/test_assertrewrite.py
@@ -2377,7 +2377,12 @@ def test_saferepr_unbounded(self):
 
 
 class TestIssue13292:
-    def test_load_cache_based_on_file_st_mtime_ns(self, pytester: Pytester) -> None:
+    """
+    Check the pyc cache generated in the 1st test execution
+    is not loaded in the 2nd test execution.
+    """
+
+    def test_stale_pyc_cache_is_not_loaded(self, pytester: Pytester) -> None:
         pytester.makepyfile("""
             def test_dummy1():
                 def func():

From 243121137452bca3c5951055ed8ac3350f1604a0 Mon Sep 17 00:00:00 2001
From: "Johnny.H" <jnhyperion@gmail.com>
Date: Fri, 14 Mar 2025 12:47:15 +0800
Subject: [PATCH 4/4] fix ut in `Windows` platform

---
 testing/test_assertrewrite.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/testing/test_assertrewrite.py b/testing/test_assertrewrite.py
index c19181cbeb3..c5770bb243e 100644
--- a/testing/test_assertrewrite.py
+++ b/testing/test_assertrewrite.py
@@ -1381,10 +1381,13 @@ def test_read_pyc_more_invalid(self, tmp_path: Path) -> None:
 
         flags = b"\x00\x00\x00\x00"
 
-        mtime = b"\x58\x3c\xb0\x5f"
+        mtime = b"\x98\xf34\x10\x91\x8b,\x18"
         mtime_int = int.from_bytes(mtime, "little")
+        # set mtime_ns for win requires integer nanoseconds
         os.utime(source, ns=(mtime_int, mtime_int))
 
+        mtime = (mtime_int & 0xFFFFFFFF).to_bytes(4, "little")
+
         size = len(source_bytes).to_bytes(4, "little")
 
         code = marshal.dumps(compile(source_bytes, str(source), "exec"))