pokemon.js

const fetch = require('node-fetch');
const fs = require('fs');

const nameExceptions = ['ho-oh', 'porygon-z', 'jangmo-o', 'hakamo-o', 'kommo-o', 'mr-mime', 'mime-jr', 'type-null', 'tapu-lele', 'tapu-fini', 'tapu-koko', 'tapu-bulu'];
const collection = {};

(async () => {
	const result = fetch('https://pokeapi.co/api/v2/pokemon?limit=100000')
		.then(res => res.text())
		.then(blob => JSON.parse(blob).results)
		.then(async array => {
			return array.map(header => {
				return fetch(header.url)
					.then(res => res.text())
					.then(blob => JSON.parse(blob))
					.then(body => {
//						console.log('processing', body.name);
						let poke = {
							name: body.name,
							height: body.height,
							weight: body.weight,
							base_stats: {
								hp: body.stats.length > 0 ? body.stats.filter(s => s.stat.name == "hp")[0].base_stat : null,
								attack: body.stats.length > 0 ? body.stats.filter(s => s.stat.name == "attack")[0].base_stat : null,
								defense: body.stats.length > 0 ? body.stats.filter(s => s.stat.name == "defense")[0].base_stat : null,
								specialAttack: body.stats.length > 0 ? body.stats.filter(s => s.stat.name == "special-attack")[0].base_stat : null,
								specialDefense: body.stats.length > 0 ? body.stats.filter(s => s.stat.name == "special-defense")[0].base_stat : null,
								speed: body.stats.length > 0 ? body.stats.filter(s => s.stat.name == "speed")[0].base_stat : null,
							},
							forms: [] //for later
						};

						return poke;
					})
					.then(poke => {
						if (poke.name.indexOf('-') == -1 || nameExceptions.includes(poke.name.toLowerCase())) {
							if (collection[poke.name]) {
								poke.forms = poke.forms.concat(collection[poke.name].forms);
							}
							collection[poke.name] = poke;
							return;
						}

						let name;

						if (poke.name.indexOf(' ') != -1) {
							name = poke.name.split(' ');
						} else {
							name = poke.name.split('-');
						}

						const baseName = name.shift();
						const formName = name.length > 1 ? name.join('-') : name[0];

//						console.log('\t\t', poke.name);

						try {
							collection[baseName] = collection[baseName] || { name: baseName, forms: [] };
							collection[baseName].forms.push(poke);
						}catch (err) {
							console.log('damn', err);
						}
					})
					.catch(err => console.log(err))
				;
			});
		})
		.catch(err => console.error(err))
	;

	//finally
	result.then((res) => {
		Promise.all(res).then(() => {
			fs.writeFileSync('./pokemon.json', JSON.stringify(Object.values(collection)));
		});
	});
})();

/**
 * Simple object check.
 * @param item
 * @returns {boolean}
 */
function isObject(item) {
  return (item && typeof item === 'object' && !Array.isArray(item));
}

/**
 * Deep merge two objects.
 * @param target
 * @param ...sources
 */
function mergeDeep(target, ...sources) {
  if (!sources.length) return target;
  const source = sources.shift();

  if (isObject(target) && isObject(source)) {
    for (const key in source) {
      if (isObject(source[key])) {
        if (!target[key]) Object.assign(target, { [key]: {} });
        mergeDeep(target[key], source[key]);
      } else {
        Object.assign(target, { [key]: source[key] });
      }
    }
  }

  return mergeDeep(target, ...sources);
}