From 85efd70a715cabd214cbe95523f96bfd236230b6 Mon Sep 17 00:00:00 2001
From: OlegP-andrew <oplisov@andrew.cmu.edu>
Date: Sun, 10 Dec 2023 23:55:28 -0500
Subject: [PATCH] Adding whitespace escaping on difference display

---
 AUTHORS                         |  1 +
 changelog/10704.improvement.rst |  1 +
 src/_pytest/assertion/util.py   | 12 ++++++++++++
 testing/test_error_diffs.py     | 14 ++++++++++++++
 4 files changed, 28 insertions(+)
 create mode 100644 changelog/10704.improvement.rst

diff --git a/AUTHORS b/AUTHORS
index e30131d1a..6f9d75e3b 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -284,6 +284,7 @@ Nicolas Delaby
 Nikolay Kondratyev
 Nipunn Koorapati
 Oleg Pidsadnyi
+Oleg Plisov
 Oleg Sushchenko
 Olga Matoula
 Oliver Bestwalter
diff --git a/changelog/10704.improvement.rst b/changelog/10704.improvement.rst
new file mode 100644
index 000000000..4c4ad4454
--- /dev/null
+++ b/changelog/10704.improvement.rst
@@ -0,0 +1 @@
+Terminal outputting string difference will now escape whitespace characters if those are the difference
diff --git a/src/_pytest/assertion/util.py b/src/_pytest/assertion/util.py
index 4d9fd114b..d3ff49ccd 100644
--- a/src/_pytest/assertion/util.py
+++ b/src/_pytest/assertion/util.py
@@ -305,10 +305,22 @@ def _diff_text(left: str, right: str, verbose: int = 0) -> List[str]:
                 left = left[:-i]
                 right = right[:-i]
     keepends = True
+    diffspace = False
+    for i in range(min(len(left), len(right))):
+        if left[i] != right[i]:
+            if left[i].isspace() and right[i].isspace():
+                diffspace = True  # Check if difference in strings is whitespace symbol
+                break
     if left.isspace() or right.isspace():
         left = repr(str(left))
         right = repr(str(right))
         explanation += ["Strings contain only whitespace, escaping them using repr()"]
+    elif diffspace:
+        left = repr(str(left))
+        right = repr(str(right))
+        explanation += [
+            "Strings are different by whitespaces, escaping them using repr()"
+        ]
     # "right" is the expected base against which we compare "left",
     # see https://github.com/pytest-dev/pytest/issues/3333
     explanation += [
diff --git a/testing/test_error_diffs.py b/testing/test_error_diffs.py
index eb7812108..723a68e49 100644
--- a/testing/test_error_diffs.py
+++ b/testing/test_error_diffs.py
@@ -262,6 +262,20 @@ TESTCASES = [
         """,
         id="Compare attrs classes",
     ),
+    pytest.param(
+        """
+        def test_this():
+            assert "word\t" == "word    "
+        """,
+        """
+        >       assert "word\t" == "word    "
+        E       AssertionError: assert 'word\\t' == 'word    '
+        E         Strings are different by whitespaces, escaping them using repr()
+        E         - 'word    '
+        E         + 'word\\t'
+        """,
+        id="Compare whitespaces",
+    ),
 ]