[Pytest-commit] Issue #615: ValueError on compound assert with percent (hpk42/pytest)

[Tom V]

New issue 615: ValueError on compound assert with percent
https://bitbucket.org/hpk42/pytest/issue/615/valueerror-on-compound-assert-with-percent

Tom V:

Assertions like `assert 1 % 1 or False` or ``assert True and 1 % 1`` fail with: `ValueError: unsupported format character ')' (0x29) at index 7`.

This behaviour is not seen with `py.test --assert=reinterp` or `--assert=plain`.

Example:

    def test_high_odd():
        n = 20
        high = n > 10
        assert high and (n % 2 > 0)

    def test_simple_percent_error():
        assert 1 % 1 and False

    # no ValueError
    def test_var_high_odd():
        n = 20
        high = n > 10
        odd = n % 2 > 0
        assert high and odd

    $ py.test percent_error.py 
    === test session starts ===
    platform linux2 -- Python 2.7.6 -- py-1.4.25 -- pytest-2.6.4.dev1
    collected 3 items 

    percent_error.py FFF

    === FAILURES ===
    ___ test_high_odd ___

        def test_high_odd():
            n = 20
            high = n > 10
    >       assert high and (n % 2 > 0)
    E       ValueError: unsupported format character ')' (0x29) at index 17

    percent_error.py:5: ValueError
    ___ test_simple_percent_error ___

        def test_simple_percent_error():
    >       assert 1 % 1 and False
    E       ValueError: unsupported format character ')' (0x29) at index 7

    percent_error.py:8: ValueError
    ___ test_var_high_odd ___

        def test_var_high_odd():
            n = 20
            high = n > 10
            odd = n % 2 > 0
    >       assert high and odd
    E       assert (True and False)

    percent_error.py:15: AssertionError
    === 3 failed in 0.01 seconds ===

Happy to have a go at writing a failing test in `TestAssertionRewrite`.