Invalid Culture when using I18N mode JSON Files

[ahofman]

Hi there,
I'm using a set of JSON files with localised strings, for example:

localization.json
localization.nl.json 

Where localization.json is the fallback locale (en-US) and localization.nl.json is Dutch.

When the request locale is nl a CultureNotFoundException is thrown with the message

Culture is not supported. (Parameter 'name')
localization is an invalid culture identifier.

from here:

Askmethat-Aspnet-JsonLocalizer/Askmethat.Aspnet.JsonLocalizer.Shared/Localizer/Modes/LocalizationI18NModeGenerator.cs

Line 49 in 788d32b

var fileCulture = new CultureInfo(fileName.Split('.')[^2] ?? String.Empty);

The issue is that the default localization.json file is being treated as a locale file, and the string.split()[^2] resolves to localization, which it then tries to create a CultureInfo from, which is invalid.