Adds a specified label to all the cards into the specified list.

AddLabelToList.js

const fetch = require('node-fetch');
const throttle = require('promise-ratelimit')(10000);

const _baseUrl = 'https://api.trello.com/1';
const _listId = '';
const _labelId = '';
const _token = '';
const _key = '';

let array = [];

Array.chunk = function (arr, len) {
  var chunks = [],
      i = 0,
      n = arr.length;

  while (i < n) {
    chunks.push(arr.slice(i, i += len));
  }

  return chunks;
};

const addLabelToCard = _url => 
  fetch(_url, {
    method: 'POST'
  })
  .then(response => {
    console.log(
      `Response: ${response.status} ${response.statusText}`
    );
    return response.text();
  })
  .then(text => console.log(text))
  .catch(err => console.error('>> Error:', err));

const getAllCards = _listId => 
  fetch(`${_baseUrl}/lists/${_listId}/cards?token=${_token}&key=${_key}`, {
    method: 'GET'
  })
    .then(response => response.json())
    .then(_cards =>
      _cards.forEach(
       _card => array.push(`${_baseUrl}/cards/${_card.id}/idLabels?token=${_token}&key=${_key}&value=${_labelId}`)
      )
    )
    .catch(err => console.error(err));

getAllCards(_listId)
  .then(() => {
    const chunks = Array.chunk(array, 99);

    for (let index = 0; index < chunks.length; index++) {
      throttle()
        .then(() => {
          const chunk = chunks[index];
          for (let k = 0; k < chunk.length; k++) {
            addLabelToCard(chunk[k]);
          }
        });
    }
  });