jwt middleware

fetchMiddleware.js

/**
 * fetchMiddleware appends a JWT to the header of each fetch action
 * and checks the response. If a 401 is encountered, it prompts for
 * a redirect to /login.
 */
const fetchMiddleware = (fetch, history) => store => next => (action) => {
  if (action.type === 'FETCH') {
    const { url, params } = action;
    const { token } = store.getState();
    if (!params.headers) {
      params.headers = {};
    }
    params.headers.token = token;
    return fetch(url, params)
      .then((response) => {
        if (response.ok) {
          return response.json();
        }
        if (response.status === 401) {
          history.push('/login');
          return response.json();
        }
        throw new Error('Network error');
      });
  }
  return next(action);
};

export default fetchMiddleware;