ricochetjs/src/whitelist.js

import fs from 'fs';
import * as readline from 'node:readline';

import log from './log.js';

export const isInWhiteList = async (filename, email) => {
  if (!email) {
    log.warn("isInWhiteList: empty email.");
    return false;
  }

  if (filename) {
    const fileStream = fs.createReadStream(filename);

    const rl = readline.createInterface({
      input: fileStream,
      crlfDelay: Infinity
    });
    // Note: we use the crlfDelay option to recognize all instances of CR LF
    // ('\r\n') in input as a single line break.

    for await (const line of rl) {
      if (email.trim() === line) {
        return true;
      }
      else {
        return false;
      }
    }

    return false;
  } else {
    log.debug('isInWhiteList: no whitelist file defined.')
    return true;
  }
}