Allow explicit default with null value

[stsewd]

This fix readthedocs/readthedocs.org#2813

• Test case
• Solution

[stsewd]

For now I'm only checking for the requirements_file default key, should I check for all defaults?

[humitos]

Good job!

I left just a comment that a test that can be added to cover the a missing case and it will be ready to merge from my point of view.

[humitos]

I think a good addition here would be this test also:

def test_parse_empty_value():
    buf = StringIO(u'base: ""')
    config = parse(buf)
    assert config[0]['base'] is ''

[agjohnson]

Looks great! I just noted a piece that could stick around for removal in a separate PR.

[agjohnson]

Let's keep this line for now, in case we have some side effects from removing a line like this.

[stsewd]

Done!

[humitos]

I think this PR is ready to be merged.

For now I'm only checking for the requirements_file default key, should I check for all defaults?

I suppose we should look for a general solution for this instead of repeat something like this for every field:

        if 'field' not in self.raw_config:
            return None
 
        field = self.raw_config['field']
        if field is None:
            return None

What do you think?

[stsewd]

@humitos I was thinking of that, but if you look closely, always there are some additional checks before the second step, and at the end, we only will save 1 line of code per method.

[stsewd]

I forgot to delete one line on the merge 🤦‍♂️

[agjohnson]

@stsewd shall we do a PR into rtd core for this as well?

[stsewd]

@agjohnson yeah!

[agjohnson]

Cool. Setting to blocking for now, we'll revisit this after.

[stsewd]

This is ported in readthedocs/readthedocs.org#4461