Wrapping fetch to handle errors

fetch-wrapper.js

var api_fetch = {
  checkStatus(response) {
    if (response.status >= 200 && response.status < 300) {
      return Promise.resolve(response);
    } else {
      return Promise.reject(response);
    }
  },

  parseJson(response) {
    return response.json();
  },

  handleError(response) {
    if (response && response.status === 401) {
      console.log('Unauthorized request', response);
    } else {
      console.log('Request failed', response);
    }
  },

  post(endpoint, body) {
    const url = `http://0.0.0.0:3000/${endpoint}`;
    const init = {
      method: "POST",
      headers: {
        "Accept": "application/json",
        "Content-Type": "application/json"
      },
      body: JSON.stringify(body)
    };

    fetch(url, init)
      .then(this.checkStatus)
      .then(this.parseJson)
      .then(function(data) {
        console.log('Request succeeded with JSON response', data);
      }).catch(this.handleError);
  }
};

api_fetch.post("login", {
  "login" : "deepak",
  "password" : "bad-password"
});

api_fetch.post("login", {
  "login" : "deepak",
  "password" : "password"
});