twitter.js

axios.interceptors.request.use((req) => {
  let { token, secret } = req;
  if (token) delete req.token;
  else token = process.env.TW_TOKEN;
  if (secret) delete req.secret;
  else secret = process.env.TW_TOKEN_SECRET;

  const oauth = {
    oauth_consumer_key: process.env.TW_KEY,
    oauth_nonce: crypto.randomBytes(20).toString('hex'),
    oauth_signature_method: 'HMAC-SHA1',
    oauth_timestamp: Math.floor(Date.now() / 1e3),
    oauth_token: token,
    oauth_version: '1.0',
  };

  Object.entries(req.params).forEach(([k, v]) => {
    if (v === undefined) delete req.params[k];
  });

  // gather all request data and encode it
  const params = Object.entries({
    ...req.params,
    ...req.body,
    ...oauth,
  })
    .map(kv => kv.map(encodeURIComponent).join('='))
    .sort()
    .join('&');

  // prepare encrypted values
  const base = [
    req.method.toUpperCase(),
    encodeURIComponent(req.baseURL + req.url),
    encodeURIComponent(params),
  ].join('&');
  const key = [
    encodeURIComponent(process.env.TW_SECRET),
    encodeURIComponent(secret),
  ].join('&');

  // encrypt values
  const signature = crypto.createHmac('sha1', key);
  signature.update(base);
  oauth.oauth_signature = signature.digest('base64');

  const header = Object.entries(oauth)
    .map(([k, v]) => `${encodeURIComponent(k)}="${encodeURIComponent(v)}"`)
    .sort()
    .join(', ');

  req.headers.Authorization = `OAuth ${header}`;
  return req;
});