auth-server-helper/lib/cookie.ts

import { run_regex } from '@sapphirecode/utilities';
import { debug } from './debug';

const logger = debug ('cookies');

type SameSiteValue = 'Lax' | 'None' | 'Strict';

interface CookieSettings {
  name: string;
  secure?: boolean;
  http_only?: boolean;
  same_site?: SameSiteValue|null;
  expires?: string;
  max_age?: number;
  domain?: string;
  path?: string;
}

const default_settings: Omit<CookieSettings, 'name'> = {
  secure:    true,
  http_only: true,
  same_site: 'Strict'
};

function build_cookie (
  settings: CookieSettings,
  value: string
): string {
  const local_settings = { ...default_settings, ...settings };
  const sections = [ `${local_settings.name}=${value}` ];

  if (local_settings.secure)
    sections.push ('Secure');
  if (local_settings.http_only)
    sections.push ('HttpOnly');
  if (
    typeof local_settings.same_site !== 'undefined'
    && local_settings.same_site !== null
  )
    sections.push (`SameSite=${local_settings.same_site}`);
  if (typeof local_settings.expires !== 'undefined')
    sections.push (`Expires=${local_settings.expires}`);
  if (typeof local_settings.max_age !== 'undefined')
    sections.push (`Max-Age=${local_settings.max_age}`);
  if (typeof local_settings.domain !== 'undefined')
    sections.push (`Domain=${local_settings.domain}`);
  if (typeof local_settings.path !== 'undefined')
    sections.push (`Path=${local_settings.path}`);

  return sections.join ('; ');
}

function extract_cookie (
  name: string|undefined,
  header: string|undefined
): string| null {
  logger (`extracting cookie ${name}`);

  const cookie_regex = /(?:^|;)\s*(?<name>[^;=]+)=(?<value>[^;]+)/gu;

  let result = null;

  run_regex (
    cookie_regex,
    header,
    (res: RegExpMatchArray) => {
      logger ('parsing cookie %s', res.groups?.name);
      if (res.groups?.name === name) {
        logger ('found cookie');
        result = res.groups?.value as string;
      }
    }
  );

  return result;
}

export { build_cookie, extract_cookie, SameSiteValue, CookieSettings };