From 0262fd300dfe521811478255af87e38008b6896b Mon Sep 17 00:00:00 2001
From: Rafi <rafi_bigdata@outlook.com>
Date: Fri, 26 Dec 2025 18:14:14 +0530
Subject: [PATCH 1/4] Preserve insertion order for extra dict items in
 assertion output

---
 src/_pytest/assertion/util.py |  4 ++--
 testing/test_assertion.py     | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/_pytest/assertion/util.py b/src/_pytest/assertion/util.py
index f35d83a6fe4..a5bcc5d02ad 100644
--- a/src/_pytest/assertion/util.py
+++ b/src/_pytest/assertion/util.py
@@ -520,7 +520,7 @@ def _compare_eq_dict(
                 + " != "
                 + highlighter(saferepr({k: right[k]}))
             ]
-    extra_left = set_left - set_right
+    extra_left = [k for k in left if k not in right]
     len_extra_left = len(extra_left)
     if len_extra_left:
         explanation.append(
@@ -529,7 +529,7 @@ def _compare_eq_dict(
         explanation.extend(
             highlighter(pprint.pformat({k: left[k] for k in extra_left})).splitlines()
         )
-    extra_right = set_right - set_left
+    extra_right = [k for k in right if k not in left]
     len_extra_right = len(extra_right)
     if len_extra_right:
         explanation.append(
diff --git a/testing/test_assertion.py b/testing/test_assertion.py
index 5179b13b0e9..a9cb1075dec 100644
--- a/testing/test_assertion.py
+++ b/testing/test_assertion.py
@@ -2198,3 +2198,36 @@ def test_vvv():
         ]
     )
     result.stdout.no_fnmatch_line(expected_non_vvv_arg_line)
+
+import re
+
+def test_dict_extra_items_preserve_insertion_order(pytester):
+    pytester.makepyfile(
+        test_order="""
+        def test_order():
+            a = {
+                "first": 1,
+                "second": 2,
+            }
+            assert a == {}
+        """
+    )
+
+    result = pytester.runpytest()
+
+    stdout = result.stdout.str()
+    stdout = re.sub(r"\x1b\[[0-9;]*m", "", stdout)
+
+    assert "Left contains 2 more items:" in stdout
+
+    dict_line = next(
+        line for line in stdout.splitlines()
+        if "{" in line and "}" in line and "first" in line
+    )
+
+    first = dict_line.find("first")
+    second = dict_line.find("second")
+
+    assert first != -1 and second != -1
+    assert first < second
+

From 5bb95f2f68150bc812a68fe562a953c02deb7eeb Mon Sep 17 00:00:00 2001
From: RafiB982 <rafi_bigdata@outlook.com>
Date: Wed, 31 Dec 2025 09:40:49 +0530
Subject: [PATCH 2/4] Fix changelog entry for #13503

---
 changelog/13503.bugfix.rst | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 changelog/13503.bugfix.rst

diff --git a/changelog/13503.bugfix.rst b/changelog/13503.bugfix.rst
new file mode 100644
index 00000000000..3c262652c38
--- /dev/null
+++ b/changelog/13503.bugfix.rst
@@ -0,0 +1,2 @@
+Preserved insertion order for extra dictionary items in assertion failure output.
+Display dictionary differences in assertion failures using the original key insertion order instead of sorted order.

From 69ce9532a01755d7fff1010b2fdf911b7abacbc7 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 31 Dec 2025 04:13:40 +0000
Subject: [PATCH 3/4] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 testing/test_assertion.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/testing/test_assertion.py b/testing/test_assertion.py
index a9cb1075dec..ae989cc9e54 100644
--- a/testing/test_assertion.py
+++ b/testing/test_assertion.py
@@ -2199,8 +2199,10 @@ def test_vvv():
     )
     result.stdout.no_fnmatch_line(expected_non_vvv_arg_line)
 
+
 import re
 
+
 def test_dict_extra_items_preserve_insertion_order(pytester):
     pytester.makepyfile(
         test_order="""
@@ -2221,7 +2223,8 @@ def test_order():
     assert "Left contains 2 more items:" in stdout
 
     dict_line = next(
-        line for line in stdout.splitlines()
+        line
+        for line in stdout.splitlines()
         if "{" in line and "}" in line and "first" in line
     )
 
@@ -2230,4 +2233,3 @@ def test_order():
 
     assert first != -1 and second != -1
     assert first < second
-

From 7e7f10096a94bcd47d731fd9d624ab8f7500731d Mon Sep 17 00:00:00 2001
From: RafiB982 <rafi_bigdata@outlook.com>
Date: Wed, 31 Dec 2025 10:03:35 +0530
Subject: [PATCH 4/4] Fix import order in test_assertion

---
 testing/test_assertion.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/testing/test_assertion.py b/testing/test_assertion.py
index ae989cc9e54..94bb6827ff6 100644
--- a/testing/test_assertion.py
+++ b/testing/test_assertion.py
@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 from collections.abc import MutableSequence
+import re
 import sys
 import textwrap
 from typing import Any
@@ -2200,9 +2201,6 @@ def test_vvv():
     result.stdout.no_fnmatch_line(expected_non_vvv_arg_line)
 
 
-import re
-
-
 def test_dict_extra_items_preserve_insertion_order(pytester):
     pytester.makepyfile(
         test_order="""