Revised formatting to work with multiple implicitly concatenated strings

AUTHORS

@@ -180,6 +180,7 @@ Jake VanderPlas
 Jakob van Santen
 Jakub Mitoraj
 James Bourbeau
+Jamie Chen
 Jan Balster
 Janne Vanhala
 Jason R. Coombs
@@ -205,6 +206,7 @@ Justice Ndou
 Justyna Janczyszyn
 Kale Kundert
 Kamran Ahmad
+Kaylin Yeoh
 Kenny Y
 Karl O. Pinc
 Karthikeyan Singaravelan

changelog/10863.bugfix.rst

@@ -0,0 +1,4 @@
+Found source causes multiline string diff error
+Added private functions to check specific cases
+Fixed output issue with implicit concatonated strings
+Added tests in test assertion file in function test_multiline_diff

testing/test_assertion.py

@@ -395,6 +395,27 @@ class TestAssert_reprcompare:
             "- eggs",
             "+ spam",
         ]
+        
+    def test_multiline_diff(self) -> None:
+        m = [
+            "This is some dummy test which shows the strange way in which Pycharm"
+            " displays the full diff."
+        ]
+        assert callequal(m, []) == [
+            "['This is som...e full diff.'] == []",
+            "Left contains one more item: 'This is some dummy test which shows the "
+            "strange way in which Pycharm displays the full diff.'",
+            'Use -v to get more diff',
+        ]
+        assert callequal(m, [], verbose=True) == [
+            "['This is som...e full diff.'] == []",
+            "Left contains one more item: 'This is some dummy test which shows the "
+            "strange way in which Pycharm displays the full diff.'",
+            "Full diff:",
+            "- []",
+            "+ ['This is some dummy test which shows the strange way in which Pycharm "
+            "displays the full diff.']",
+        ]
 
     def test_text_skipping(self) -> None:
         lines = callequal("a" * 50 + "spam", "a" * 50 + "eggs")