Feature Request: catalogs

[SumNeuron]

So I was looking through your code and was hoping you an explain some things.

For example you do not have exposed the catalogs api, so I think this would work, but I am not sure.

// src/scryfall.ts

//...
import { ScryfallCatalog } from "./ScryfallCatalog";
//...

/**
 * The list of all known catalogs currated by Scryfall itself. Currently there 
 * is no endpoint (e.g. api.scryfall.com/catalogs), which returns what catalogs
 * exists. 
 
 * Each entry in this list is the trailing slug of https://api.scryfall.com/catalog/
 */
const knownCatalogs = [
  'card-names',
  'artist-names',
  'word-bank',
  'creature-types',
  'planeswalker-types',
  'land-types',
  'artifact-types',
  'enchantment-types',
  'spell-types',
  'powers',
  'toughnesses',
  'loyalties',
  'watermarks',
]
/**
 * Attempts to fetch the catalog of the given name, returning the list of its entries
 * @param name The name of the catalog to fetch
 * @returns A promise, if no callback is specified. Otherwise nothing.
 */
export function getCatalog(
  name: string,
  cb: (res: ScryfallCatalog) => void,
): Promise<ScryfallCatalog> {
  const ret = (res, rej) => {
    const isValid = !(knownCatalogs.indexOf(name.toLowerCase().replaced(' ', '-')) < 0)
    const err = new Error(`${name} is not a known catalog`);
    if (!isValid) rej(err)
    
    APIRequest(`/catalog/${name}`, (catalog: ScryfallError | ScryfallCatalog) => {
        if (catalog.object === "error") {
            rej ? rej(catalog) : res(catalog);
        } else {
            rej ? res(catalog) : res(null, catalog);
        }
    });
  }
  if (cb) {
      ret(cb, null);
  } else {
      return new Promise<ScryfallCatalog>((resolve, reject) => ret(resolve, reject));
  }
}

basically I am not the most familiar with typescript... and also I am not so sure what your callback is doing?

[SumNeuron]

https://github.com/SumNeuron/scryfall/branches