Wrong diff in case of dictionary has dotted keys in ignore in dictdiffer.

[jyoti-arora1991]

Issue occurring on dictdiffer-0.7.1.

Lets take two dictionaries:

config_dict = OrderedDict([('address', 'devops011-slv-01.gvs.ggn'),('nifi.zookeeper.session.timeout', '3 secs')])

ref_dict = OrderedDict([('address', 'devops011-slv-01.gvs.ggn'),('nifi.zookeeper.session.timeout', '4 secs')])

list(diff(config_dict, ref_dict,ignore=set(['nifi.zookeeper.session.timeout'])))

Output for above is:

[('change', ['nifi.zookeeper.session.timeout'], ('3 secs', '4 secs'))]

seems like ignore functionality is not working when we pass dotted key in ignore set.

[yoyonel]

I write a fix/patch to workaround this problem: feature/Issue#107

My solution is to provide a function to generate raw ignored keys.

I define a RAW_IGNORE_KEY_TOKEN to generate (prefix) raw ignored keys (in utils.py).
I use this functionnality in diff function for updating elements in ignore list keys:

if isinstance(ignore, Iterable):
        def _unmake_raw_ignore_key(key):
            return key[len(RAW_IGNORE_KEY_TOKEN):]

        def _is_raw_ignore_key(key):
            return key.startswith(RAW_IGNORE_KEY_TOKEN)

        def _process_ignore_value(value):
            if isinstance(value, int):
                return value,
            elif isinstance(value, list):
                return tuple(value)
            elif isinstance(value, string_types) and _is_raw_ignore_key(value):
                return _unmake_raw_ignore_key(value),
            return value

        ignore = type(ignore)(_process_ignore_value(value) for value in ignore)

Usage in unittest:

def test_ignore_dotted_key_disable(self):
        key_to_ignore = u'nifi.zookeeper.session.timeout'
        config_dict = OrderedDict(
            [('address', 'devops011-slv-01.gvs.ggn'),
             (key_to_ignore, '3 secs')])

        ref_dict = OrderedDict(
            [('address', 'devops011-slv-01.gvs.ggn'),
             (key_to_ignore, '4 secs')])

        assert len(
            list(diff(config_dict, ref_dict,
                      ignore=[make_raw_ignore_key(key_to_ignore)]))) == 0

@jirikuncar Sound good for you ? (if yes, i can PR my branch)

[yoyonel]

A simpler (better) approach with simple custom type to indicate dotted ignore key: feature/Issue#107_oo

Custom type in utils.py:

class DottedIgnoreKey(str):
    """Custom type to specify dotted ignore key.

    This custom type help to desactivate dotted interpretation.
    """

    pass

Using in diff function in init.py:

def _process_ignore_value(value):
            if isinstance(value, int):
                return value,
            elif isinstance(value, list):
                return tuple(value)
            elif isinstance(value, DottedIgnoreKey):
                return str(value),
            return value

and finally in unit test test_dictdiffer.py:

def test_ignore_dotted_ignore_key(self):
        key_to_ignore = u'nifi.zookeeper.session.timeout'
        config_dict = OrderedDict(
            [('address', 'devops011-slv-01.gvs.ggn'),
             (key_to_ignore, '3 secs')])

        ref_dict = OrderedDict(
            [('address', 'devops011-slv-01.gvs.ggn'),
             (key_to_ignore, '4 secs')])

        assert len(
            list(diff(config_dict, ref_dict,
                      ignore=[DottedIgnoreKey(key_to_ignore)]))) == 0

Work fine with minimal modifications impact in code base :-D