to_superlative.js

'use strict';
const convertables = require('../../data/convertables.js');

const to_superlative = function(str) {
  const irregulars = {
    'nice': 'nicest',
    'late': 'latest',
    'hard': 'hardest',
    'inner': 'innermost',
    'outer': 'outermost',
    'far': 'furthest',
    'worse': 'worst',
    'bad': 'worst',
    'good': 'best'
  };

  const dont = {
    'overweight': 1,
    'ready': 1
  };

  const transforms = [{
    'reg': /y$/i,
    'repl': 'iest'
  }, {
    'reg': /([aeiou])t$/i,
    'repl': '$1ttest'
  }, {
    'reg': /([aeou])de$/i,
    'repl': '$1dest'
  }, {
    'reg': /nge$/i,
    'repl': 'ngest'
  }];

  const matches = [
    /ght$/,
    /nge$/,
    /ough$/,
    /ain$/,
    /uel$/,
    /[au]ll$/,
    /ow$/,
    /oud$/,
    /...p$/
  ];

  const not_matches = [
    /ary$/
  ];

  const generic_transformation = function(s) {
    if (s.match(/e$/)) {
      return s + 'st';
    }
    return s + 'est';
  };

  for (let i = 0; i < transforms.length; i++) {
    if (str.match(transforms[i].reg)) {
      return str.replace(transforms[i].reg, transforms[i].repl);
    }
  }

  if (convertables.hasOwnProperty(str)) {
    return generic_transformation(str);
  }

  if (dont.hasOwnProperty(str)) {
    return 'most ' + str;
  }

  if (irregulars.hasOwnProperty(str)) {
    return irregulars[str];
  }
  for (let i = 0; i < not_matches.length; i++) {
    if (str.match(not_matches[i])) {
      return 'most ' + str;
    }
  }

  for (let i = 0; i < matches.length; i++) {
    if (str.match(matches[i])) {
      return generic_transformation(str);
    }
  }
  return 'most ' + str;
};