gh-111019: Align expected and actual titles in test output (#111020)

Align expected and actual titles in output from
assert_has_calls/assert_called_with for greater readability

Author: morisja

Lib/test/test_unittest/testmock/testmock.py

@@ -1058,7 +1058,7 @@ def test_assert_called_with_failure_message(self):
 
         actual = 'not called.'
         expected = "mock(1, '2', 3, bar='foo')"
-        message = 'expected call not found.\nExpected: %s\nActual: %s'
+        message = 'expected call not found.\nExpected: %s\n  Actual: %s'
         self.assertRaisesWithMsg(
             AssertionError, message % (expected, actual),
             mock.assert_called_with, 1, '2', 3, bar='foo'
@@ -1073,7 +1073,7 @@ def test_assert_called_with_failure_message(self):
         for meth in asserters:
             actual = "foo(1, '2', 3, foo='foo')"
             expected = "foo(1, '2', 3, bar='foo')"
-            message = 'expected call not found.\nExpected: %s\nActual: %s'
+            message = 'expected call not found.\nExpected: %s\n  Actual: %s'
             self.assertRaisesWithMsg(
                 AssertionError, message % (expected, actual),
                 meth, 1, '2', 3, bar='foo'
@@ -1083,7 +1083,7 @@ def test_assert_called_with_failure_message(self):
         for meth in asserters:
             actual = "foo(1, '2', 3, foo='foo')"
             expected = "foo(bar='foo')"
-            message = 'expected call not found.\nExpected: %s\nActual: %s'
+            message = 'expected call not found.\nExpected: %s\n  Actual: %s'
             self.assertRaisesWithMsg(
                 AssertionError, message % (expected, actual),
                 meth, bar='foo'
@@ -1093,7 +1093,7 @@ def test_assert_called_with_failure_message(self):
         for meth in asserters:
             actual = "foo(1, '2', 3, foo='foo')"
             expected = "foo(1, 2, 3)"
-            message = 'expected call not found.\nExpected: %s\nActual: %s'
+            message = 'expected call not found.\nExpected: %s\n  Actual: %s'
             self.assertRaisesWithMsg(
                 AssertionError, message % (expected, actual),
                 meth, 1, 2, 3
@@ -1103,7 +1103,7 @@ def test_assert_called_with_failure_message(self):
         for meth in asserters:
             actual = "foo(1, '2', 3, foo='foo')"
             expected = "foo()"
-            message = 'expected call not found.\nExpected: %s\nActual: %s'
+            message = 'expected call not found.\nExpected: %s\n  Actual: %s'
             self.assertRaisesWithMsg(
                 AssertionError, message % (expected, actual), meth
             )
@@ -1552,7 +1552,7 @@ def f(x=None): pass
                 '^{}$'.format(
                     re.escape('Calls not found.\n'
                               'Expected: [call()]\n'
-                              'Actual: [call(1)]'))) as cm:
+                              '  Actual: [call(1)]'))) as cm:
             mock.assert_has_calls([call()])
         self.assertIsNone(cm.exception.__cause__)
 
@@ -1564,7 +1564,7 @@ def f(x=None): pass
                         'Error processing expected calls.\n'
                         "Errors: [None, TypeError('too many positional arguments')]\n"
                         "Expected: [call(), call(1, 2)]\n"
-                        'Actual: [call(1)]'))) as cm:
+                        '  Actual: [call(1)]'))) as cm:
             mock.assert_has_calls([call(), call(1, 2)])
         self.assertIsInstance(cm.exception.__cause__, TypeError)
 

Lib/unittest/mock.py

@@ -857,7 +857,7 @@ def _format_mock_call_signature(self, args, kwargs):
 
 
     def _format_mock_failure_message(self, args, kwargs, action='call'):
-        message = 'expected %s not found.\nExpected: %s\nActual: %s'
+        message = 'expected %s not found.\nExpected: %s\n  Actual: %s'
         expected_string = self._format_mock_call_signature(args, kwargs)
         call_args = self.call_args
         actual_string = self._format_mock_call_signature(*call_args)
@@ -960,7 +960,7 @@ def assert_called_with(self, /, *args, **kwargs):
         if self.call_args is None:
             expected = self._format_mock_call_signature(args, kwargs)
             actual = 'not called.'
-            error_message = ('expected call not found.\nExpected: %s\nActual: %s'
+            error_message = ('expected call not found.\nExpected: %s\n  Actual: %s'
                     % (expected, actual))
             raise AssertionError(error_message)
 
@@ -1011,7 +1011,7 @@ def assert_has_calls(self, calls, any_order=False):
                 raise AssertionError(
                     f'{problem}\n'
                     f'Expected: {_CallList(calls)}'
-                    f'{self._calls_repr(prefix="Actual").rstrip(".")}'
+                    f'{self._calls_repr(prefix="  Actual").rstrip(".")}'
                 ) from cause
             return