Datetime tester feeds optional params; need tests with only positional args

[ChanceNCounter]

The standardization pass on parse_de.py seems to have messed up certain cases that weren't detected until the update made it all the way to Mycroft-core.

It's the datetime tester. The datetime tester has both the optional params populated in all languages. This inherently misses all nondefault invocations. Glaring oversight. At least seven programmers and four reviewers, including myself.

This ticket could be an adage about impostor syndrome, Dunning-Kruger, and the fictional nature of 100% test coverage.

[ChanceNCounter]

For example, extract_datetime('2 wochen') and extract_datetime(2 tage) both fail in the absence of an explicitly-passed anchor date.

These calls passed in LF 0.2.3, and the change didn't make any tests fail. We discovered the problem when a German-speaking Mycroft user tried it.

[emphasize]

I don't think this would be caught on any language since the tests always give an anchorDate

date = datetime(2017, 6, 27, 0, 0)
[extractedDate, leftover] = extract_datetime(text, date)

suggestion would be to throw in some tests without the need to set a specific date

eg

heute=lingua_franca.time.now_local()
def test_extractdatetime_de(self):
        def testExtract(text, expected_date, expected_leftover):
            kwargs={"lang":"de-de"}
            if isinstance(expected_date,str):
                kwargs["anchorDate"]=datetime(2017, 6, 27, 0, 0)
            else:
                expected_date=expected_date.replace(hour=0, minute=0, second=0).strftime("%Y-%m-%d %H:%M:%S")

            extractedDate, leftover = extract_datetime(text, **kwargs)
            extractedDate = extractedDate.strftime("%Y-%m-%d %H:%M:%S")

            self.assertEqual(extractedDate, expected_date)
            self.assertEqual(leftover, expected_leftover)

        testExtract("setze den frisörtermin auf 5 tage von heute",
                    heute+timedelta(days=5), "setze frisörtermin")

[ChanceNCounter]

Agreed. I think some/most of this still involves those JSON parsers, so it'll be more than a five-minute fix.

Take a stab, if you like; if not, I'll throw it on the roadmap thingy.