Text differences

When showing the explanation for short strings, pytest uses a simple difference method:

_____________________ test_default_player_class _____________________

    def test_default_player_class():
        x = get_default_player_class()
>       assert x == 'sorcerer'
E       AssertionError: assert 'warrior' == 'sorcerer'
E         - warrior
E         + sorcerer

Longer strings show a smarter delta, using difflib.ndiff to quickly spot the differences:

__________________ test_warrior_short_description ___________________

    def test_warrior_short_description():
        desc = get_short_class_description('warrior')
>       assert desc == 'A battle-hardened veteran, can equip heavy armor and weapons.'
E       AssertionError: assert 'A battle-har... and weapons.' == 'A battle-hard... and weapons.'
E         - A battle-hardened veteran, favors heavy armor and weapons.
E         ?                            ^ ^^^^
E         + A battle-hardened veteran, can equip heavy armor and weapons.
E         ?                            ^ ^^^^^^^

Multiline strings are also treated specially:

    def test_warrior_long_description():
        desc = get_long_class_description('warrior')
>       assert desc == textwrap.dedent('''\
            A seasoned veteran of many battles. Strength and Dexterity
            allow to yield heavy armor and weapons, as well as carry
            more equipment. Weak in magic.
            ''')
E       AssertionError: assert 'A seasoned v... \n' == 'A seasoned ve... \n'
E         - A seasoned veteran of many battles. High Strength and Dexterity
E         ?                                     -----
E         + A seasoned veteran of many battles. Strength and Dexterity
E           allow to yield heavy armor and weapons, as well as carry
E         - more equipment while keeping a light roll. Weak in magic.
E         ?               ---------------------------
E         + more equipment. Weak in magic.