fontoxml-localization-tools 
Tools for working with FontoXML localization bundles.
Installation
npm i -g fontoxml-localization-tools
Usage
fontoxml-localization-tool help
prints this message
fontoxml-localization-tool extract [path [path...]]
extract message bundle template from package(s) at the given path(s)
fontoxml-localization-tool merge [path [path...]]
merge message bundles
fontoxml-localization-tool update [--overwrite] <bundlePath> <templatePath>
update message bundle with new template, overwriting the source if --overwrite is passed
Message bundles
Message bundles are JSON files, containing an array of Message objects. Each Message contains an in property with the
original message, and an out property set to the localized version. Optionally, messages may contain a meta
property with information about the location of the message in the source code. When merging messages with the same in
value but conflicting out values, a conflicts property is created to preserve the other localizations.
Messages in the in and out properties follow the ICU MessageFormat standard. Please refer to the
messageformat.js documentation for an overview of the syntax options.
Message bundles should be placed directly in the src folder of a FontoXML package. Message bundles should be named
messages.${locale}.json, where ${locale} is the IETF language code for the locale the messages belong to. Make sure
to use the appropriate code from the CLDR plural rules chart
in order for the correct plural forms to be used for your localization.