[CLDR Error] Serbian Locale data cannot load

[allen138]

Bug Description

Hi team,
There is a discrepancy between openUI5 sap.ui.core.LocaleData and the ui5 webcomponent asset-registries.LocaleData when the locale is Serbian "sh". The ui5-wc code has a mapping that converts 'sh' to 'sr' M_ISO639_OLD_TO_NEW LocaleData.js#L16 while sap.ui.core.LocaleData converts 'sh' to 'sr_Latn' sap.ui.core.LocaleData.js#L2079-L2083. This discrepancy will cause a CLDR error on line asset-registries/LocaleData.js#L95. This can happen when you use the date formatter calling fetchCldr. ex:

import DateFormat from "@ui5/webcomponents-localization/dist/DateFormat";
import { fetchCldr } from "@ui5/webcomponents-base/dist/asset-registries/LocaleData.js";
import getUserLocale from "@ui5/webcomponents-localization/dist/locale/getLocaleData";

export function getDateFormatter(pattern, cal) {
   (async () => {
      await fetchCldr(await getUserLocale());
      return DateFormat.getInstance({
        pattern: pattern,
        calendarType: cal
      });
   })();
};

getLocaleData will internally create a new LocaleData instance via sap.ui.core.LocaleData and through the constructor is will call getData ui5-wc getLocaleData.js#L21 -> [sap.ui.core.LocaleData.js#L28 constructor|https://github.com/SAP/openui5/blob/master/src/sap.ui.core/src/sap/ui/core/LocaleData.js#L28]. Loader extension calls getLocaleData with the wrong locale: [LoaderExtensions.js#L10|https://github.com/SAP/ui5-webcomponents/blob/v1.1.2/packages/localization/src/sap/base/util/LoaderExtensions.js#L10] and it fails to fallback to English because the localeDataMap only has the 'sr' object in its mapping. Please see:
'sr_Latn' locale being passed to getLocaleData:

supported locale map:

loader map:

localeDataMap

Stack:

Expected Behavior

1. ui5-wc should accept 'sr_Latn' as a supported locale
2. no CLDR error should occur when locale is Serbian
3. Since ui5-wc uses openui5 under the covers, internal logic should align.

Steps to Reproduce

1. Please reach out to me via our internal slack channel if you need an instance and replication steps.

Priority

• Low

• Medium

• High

• Very High

• Organization: SF

• Business impact: High

[allen138]

Note, This issue occurs with the upgrade to the stable version 1.2.x (uses openUI5 1.94.0), prior I was using 0.31.27 which used openui5 version 1.76.0 and in that version the Serbian logic was the same.
https://github.com/SAP/ui5-webcomponents/blob/v0.31.27/packages/localization/package.json#L26
https://github.com/SAP/openui5/blob/1.76.0/src/sap.ui.core/src/sap/ui/core/LocaleData.js#L3186