Updated diff to show \t in string comparison assertions

AUTHORS

@@ -121,6 +121,7 @@ Eduardo Schettino
 Eli Boyarski
 Elizaveta Shashkova
 Éloi Rivard
+Emmeline Wetzel
 Endre Galaczi
 Eric Hunsberger
 Eric Liu
@@ -220,6 +221,7 @@ Loic Esteve
 Lukas Bednar
 Luke Murphy
 Maciek Fijalkowski
+Madeline Thai-Tang
 Maho
 Maik Figura
 Mandeep Bhutani

changelog/10704.improvement.rst

@@ -0,0 +1 @@
+Changed the diff explanation for string comparison assertions when there is a tab in the string to show ``\t`` instead of four spaces.

src/_pytest/assertion/util.py

@@ -289,6 +289,10 @@ def _diff_text(left: str, right: str, verbose: int = 0) -> List[str]:
         line.strip("\n")
         for line in ndiff(right.splitlines(keepends), left.splitlines(keepends))
     ]
+    for i in range(len(explanation)):
+        if "?    " not in explanation[i]:  # dont replace diff message tab
+            explanation[i] = explanation[i].replace("+     ", "+ \\t")
+            explanation[i] = explanation[i].replace("    ", "\\t")
     return explanation
 
 

testing/test_error_diffs.py

@@ -262,6 +262,23 @@ def test_this():
         """,
         id="Compare attrs classes",
     ),
+    pytest.param(
+        """
+        def test_this():
+            result =   '''spam    bacon
+            eggs love'''
+            desired = "spam bacon eggs love"
+            assert result == desired
+        """,
+        """
+        >       assert result == desired
+        E       AssertionError: assert 'spam    bacon\\n    eggs love' == 'spam bacon eggs love'
+        E         - spam bacon eggs love
+        E         + spam\\tbacon
+        E         + \\teggs love
+        """,
+        id="Test tab repr in diff",
+    ),
 ]