index.js

import got from 'got'

/*
* Returns `got` wrapped with cache to be used as normal got
*/

export default function gotCached(config) {
  if (!config.cache) throw Error('cache is a required option')

  const { cache } = config

  function setCache(key, value, options) {
    if(options.json) value = JSON.stringify(value)

    cache.set(key, value)
  }

  function getCache(key, options) {
    return cache.get(key)
      .then(value => {
        if (!value) return null
        if (options.json) value = JSON.parse(value)

        return Promise.resolve({
          status: 200,
          body: value
        })
      })
  }

  function cachingGot(url, options) {
    return got(url, options).then(response => {
      setCache(url, response.body, options)

      return Promise.resolve(response)
    })
  }

  function cachedGot(url, options = {}) {
    // return plain got for non-GET requests
    if (options.method && options.method !== 'GET') {
      return got(url, options)
    }

    return getCache(url, options)
      .then(cached => {
        // return the cached result if it exist
        if(cached) return cached

        // return got response after setting cache
        return cachingGot(url, options)
      })
  }

  return Object.assign(cachedGot, got, {
    get: (url, options) => cachedGot(url, options)
  })
}