react-relay-network-modern/es/middlewares/auth.js

Network Layer for React Relay and Express (Batch Queries, AuthToken, Logging, Retry)

/* eslint-disable no-param-reassign, arrow-body-style, dot-notation */
import { isFunction } from '../utils';
import RRNLError from '../RRNLError';
export class RRNLAuthMiddlewareError extends RRNLError {
  constructor(msg) {
    super(msg);
    this.name = 'RRNLAuthMiddlewareError';
  }
}
export default function authMiddleware(opts) {
  const {
    token: tokenOrThunk,
    tokenRefreshPromise,
    allowEmptyToken = false,
    prefix = 'Bearer ',
    header = 'Authorization'
  } = opts || {};
  let tokenRefreshInProgress = null;
  return next => async req => {
    try {
      // $FlowFixMe
      const token = await (isFunction(tokenOrThunk) ? tokenOrThunk(req) : tokenOrThunk);
      if (!token && tokenRefreshPromise && !allowEmptyToken) {
        throw new RRNLAuthMiddlewareError('Empty token');
      }
      if (token) {
        req.fetchOpts.headers[header] = `${prefix}${token}`;
      }
      const res = await next(req);
      return res;
    } catch (e) {
      if (e && tokenRefreshPromise) {
        if (e.message === 'Empty token' || e.res && e.res.status === 401) {
          if (tokenRefreshPromise) {
            if (!tokenRefreshInProgress) {
              tokenRefreshInProgress = Promise.resolve(tokenRefreshPromise(req, e.res)).then(newToken => {
                tokenRefreshInProgress = null;
                return newToken;
              }).catch(err => {
                tokenRefreshInProgress = null;
                throw err;
              });
            }
            return tokenRefreshInProgress.then(newToken => {
              if (!newToken && !allowEmptyToken) {
                throw new RRNLAuthMiddlewareError('Empty token');
              }
              const newReq = req.clone();
              if (newToken) {
                newReq.fetchOpts.headers[header] = `${prefix}${newToken}`;
              } else {
                delete newReq.fetchOpts.headers[header];
              }
              return next(newReq); // re-run query with new token
            });
          }
        }
      }

      throw e;
    }
  };
}