next-intl/dist/esm/development/navigation/shared/syncLocaleCookie.js

Internationalization (i18n) for Next.js

import { getBasePath } from './utils.js';

/**
 * We have to keep the cookie value in sync as Next.js might
 * skip a request to the server due to its router cache.
 * See https://github.com/amannn/next-intl/issues/786.
 */
function syncLocaleCookie(localeCookie, pathname, locale, nextLocale) {
  const isSwitchingLocale = nextLocale !== locale && nextLocale != null;
  if (!localeCookie || !isSwitchingLocale ||
  // Theoretical case, we always have a pathname in a real app,
  // only not when running e.g. in a simulated test environment
  !pathname) {
    return;
  }
  const basePath = getBasePath(pathname);
  const hasBasePath = basePath !== '';
  const defaultPath = hasBasePath ? basePath : '/';
  const {
    name,
    ...rest
  } = localeCookie;
  if (!rest.path) {
    rest.path = defaultPath;
  }
  let localeCookieString = `${name}=${nextLocale};`;
  for (const [key, value] of Object.entries(rest)) {
    // Map object properties to cookie properties.
    // Interestingly, `maxAge` corresponds to `max-age`,
    // while `sameSite` corresponds to `SameSite`.
    // Also, keys are case-insensitive.
    const targetKey = key === 'maxAge' ? 'max-age' : key;
    localeCookieString += `${targetKey}`;
    if (typeof value !== 'boolean') {
      localeCookieString += '=' + value;
    }

    // A trailing ";" is allowed by browsers
    localeCookieString += ';';
  }

  // Note that writing to `document.cookie` doesn't overwrite all
  // cookies, but only the ones referenced via the name here.
  document.cookie = localeCookieString;
}

export { syncLocaleCookie as default };