[DE DateTimeV2] Duration issue with double numbers due to incorrect toString call

[stegreiwe]

In the date time recognition seems to be a culture dependent issue in the calculation of a duration in System.Threading.Thread.CurrentThread.CurrentCulture = "de-DE" environments.

A german sentence "Wir haben anderthalb Stunden gewartet." > engl. "We waited one and a half hours." translates into a Timex PT15H, but
the result should be PT1.5H

In line 201 of the current BaseDurationParser.cs

numVal = double.Parse(pr.Value.ToString(), CultureInfo.InvariantCulture) + ParseNumberWithUnitAndSuffix(suffixStr);

pr.Value contains the correct double value of 1.5, but ToString() reformats this to "1,5" (with comma because of de-DE) and the invariant double.Parse makes 15 out of it in result.

When doing for example
var valueAsString = Convert.ToString(pr.Value, CultureInfo.InvariantCulture);
numVal = double.Parse(valueAsString, CultureInfo.InvariantCulture) + ParseNumberWithUnitAndSuffix(suffixStr);
instead,
numVal gets the correct value of 1.5, even when the threading culture is German

[tellarin]

@stegreiwe, thanks for catching this! Would you be able to create a PR with the corresponding fix and a test case showing the correct behaviour? If that's not possible, we'll try to add the fix ASAP.

[stegreiwe]

Oh, thx for recognizing this issue.

You do have the sentence already in your German test cases. That's where I got it from. Maybe it makes sense to change the Thread-Culture at the beginning of the tests. It would have been issued then directly from your test cases.