Fix clearable

[byronz]

this PR fixes both #593 and #594

[byronz]

there are numerous requests on circleci community about conditional Jobs upon previous failure. right now, the behavior is when the previous job fails, the percy finalize job cannot be executed.

a compromise for now as a percy clean up when failed

[byronz]

this is an idea I have in mind to associate the test case with issue number, could be helpful for test selection by associating the test case with the issue

[alexcjohnson]

@byronz we can keep this if it's useful, but we should do something to clear the warning it currently gives:

/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/_pytest/mark/structures.py:324: PytestUnknownMarkWarning:
Unknown pytest.mark.DCC594 - is this a typo? You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/latest/mark.html

[Marc-Andre-Rivet]

While the previous code was not optimal in terms of setProps, it would have updated the values in all cases. Now this won't update if one is unset, whether updatemode is single or both. Rather than preventing the update if one of start/end was not previously set, could instead check and add each individually if the "global" condition is met.

e.g.

if (clearable && (!start_date || !end_date)) {
    const props = { };
    if (!start_date && oldMomentDates.start_date) {
        props.start_date = null;
    }
    // idem for end_date

    setProps(props);
}

[byronz]

@Marc-Andre-Rivet when you click the x, both start and end will be set to null, the condition can be either one date changed .