@chubbyts/chubbyts-negotiation/dist/accept-language-negotiator.js

A simple negotiation library.

import { resolveHeaderToMap } from './negotiation.js';
const compareLanguage = (locale, supportedValues, attributes) => {
    const localeParts = locale.match(/([^-]+)-([^-]+)$/);
    if (null === localeParts) {
        return undefined;
    }
    const language = localeParts[1];
    if (supportedValues.some((supportedLocale) => supportedLocale === language)) {
        return { value: language, attributes };
    }
    return undefined;
};
const compareAcceptLanguages = (supportedValues, headerToMap) => {
    for (const [locale, attributes] of headerToMap.entries()) {
        if (-1 !== supportedValues.indexOf(locale)) {
            return { value: locale, attributes };
        }
    }
    for (const [locale, attributes] of headerToMap.entries()) {
        const negotiatedValue = compareLanguage(locale, supportedValues, attributes);
        if (undefined !== negotiatedValue) {
            return negotiatedValue;
        }
    }
    if (headerToMap.has('*')) {
        return { value: supportedValues[0], attributes: headerToMap.get('*') };
    }
    return undefined;
};
export const createAcceptLanguageNegotiator = (supportedValues) => {
    return {
        negotiate: (header) => {
            const headerToMap = resolveHeaderToMap(header);
            return compareAcceptLanguages(supportedValues, headerToMap);
        },
        supportedValues,
    };
};