function defineLocale()

in charts/shared/moment.js [2135:2187]
46 lines of code
8 McCabe index (conditional complexity)

function defineLocale(name, config) {
    if (config !== null) {
        var locale,
            parentConfig = baseConfig;
        config.abbr = name;
        if (locales[name] != null) {
            deprecateSimple(
                'defineLocaleOverride',
                'use moment.updateLocale(localeName, config) to change ' +
                    'an existing locale. moment.defineLocale(localeName, ' +
                    'config) should only be used for creating a new locale ' +
                    'See http://momentjs.com/guides/#/warnings/define-locale/ for more info.'
            );
            parentConfig = locales[name]._config;
        } else if (config.parentLocale != null) {
            if (locales[config.parentLocale] != null) {
                parentConfig = locales[config.parentLocale]._config;
            } else {
                locale = loadLocale(config.parentLocale);
                if (locale != null) {
                    parentConfig = locale._config;
                } else {
                    if (!localeFamilies[config.parentLocale]) {
                        localeFamilies[config.parentLocale] = [];
                    }
                    localeFamilies[config.parentLocale].push({
                        name: name,
                        config: config,
                    });
                    return null;
                }
            }
        }
        locales[name] = new Locale(mergeConfigs(parentConfig, config));

        if (localeFamilies[name]) {
            localeFamilies[name].forEach(function (x) {
                defineLocale(x.name, x.config);
            });
        }

        // backwards compat for now: also set the locale
        // make sure we set the locale AFTER all child locales have been
        // created, so we won't end up with the child locale set.
        getSetGlobalLocale(name);

        return locales[name];
    } else {
        // useful for testing
        delete locales[name];
        return null;
    }
}