eslint collect errors warnings counted

count-eslint-errors.js

// copy eslint output here replace ` to ' before copying to avoid js error
str = ``;

str.split(/\n/)
  // get rules from the lines containing warning or error
  .map(t => {
    const match = t.match(/^\s+(\d+\:\d+).+\s+([0-9@_\/\-a-zA-Z]+)$/);

    return match && match[2];
  })
  // remove nulls
  .filter(i => i)
  // create object with count
  .reduce((acc, rule) => ({...acc, [rule]: acc[rule] ? acc[rule] + 1 : 1}), {})