movieLists.json

[
  {
    "name": "Instant Queue",
    "videos": [
      {
        "id": 70111470,
        "title": "Die Hard",
        "boxarts": [
          {
            "width": 150,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/DieHard150.jpg"
          },
          {
            "width": 200,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/DieHard200.jpg"
          }
        ],
        "url": "http:\/\/api.netflix.com\/catalog\/titles\/movies\/70111470",
        "rating": 4,
        "bookmark": [
          
        ]
      },
      {
        "id": 654356453,
        "title": "Bad Boys",
        "boxarts": [
          {
            "width": 200,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/BadBoys200.jpg"
          },
          {
            "width": 150,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/BadBoys150.jpg"
          }
        ],
        "url": "http:\/\/api.netflix.com\/catalog\/titles\/movies\/70111470",
        "rating": 5,
        "bookmark": [
          {
            "id": 432534,
            "time": 65876586
          }
        ]
      }
    ]
  },
  {
    "name": "New Releases",
    "videos": [
      {
        "id": 65432445,
        "title": "The Chamber",
        "boxarts": [
          {
            "width": 150,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/TheChamber150.jpg"
          },
          {
            "width": 200,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/TheChamber200.jpg"
          }
        ],
        "url": "http:\/\/api.netflix.com\/catalog\/titles\/movies\/70111470",
        "rating": 4,
        "bookmark": [
          
        ]
      },
      {
        "id": 675465,
        "title": "Fracture",
        "boxarts": [
          {
            "width": 200,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/Fracture200.jpg"
          },
          {
            "width": 150,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/Fracture150.jpg"
          },
          {
            "width": 300,
            "height": 200,
            "url": "http:\/\/cdn-0.nflximg.com\/images\/2891\/Fracture300.jpg"
          }
        ],
        "url": "http:\/\/api.netflix.com\/catalog\/titles\/movies\/70111470",
        "rating": 5,
        "bookmark": [
          {
            "id": 432534,
            "time": 65876586
          }
        ]
      }
    ]
  }
]

parse-movie-lists.js

// Given a list of movies in JSON format (taken from the tutorial at http://reactivex.io/learnrx/),
// retrieve id, title, and a 150x200 box art url for every one.

async function getAllMovies(endpoint) {
  // Do some fetch operation to get the movie list json from an endpoint
  // return await movieLists.json()
  return await JSON.parse('[{"name":"Instant Queue","videos":[{"id":70111470,"title":"Die Hard","boxarts":[{"width":150,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg"},{"width":200,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/DieHard200.jpg"}],"url":"http://api.netflix.com/catalog/titles/movies/70111470","rating":4,"bookmark":[]},{"id":654356453,"title":"Bad Boys","boxarts":[{"width":200,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/BadBoys200.jpg"},{"width":150,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/BadBoys150.jpg"}],"url":"http://api.netflix.com/catalog/titles/movies/70111470","rating":5,"bookmark":[{"id":432534,"time":65876586}]}]},{"name":"New Releases","videos":[{"id":65432445,"title":"The Chamber","boxarts":[{"width":150,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/TheChamber150.jpg"},{"width":200,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/TheChamber200.jpg"}],"url":"http://api.netflix.com/catalog/titles/movies/70111470","rating":4,"bookmark":[]},{"id":675465,"title":"Fracture","boxarts":[{"width":200,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg"},{"width":150,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg"},{"width":300,"height":200,"url":"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg"}],"url":"http://api.netflix.com/catalog/titles/movies/70111470","rating":5,"bookmark":[{"id":432534,"time":65876586}]}]}]')
}

function flatten(listOfLists) {
  return listOfLists.reduce((acc, list) => [...acc, ...list], [])
}

function flatMapAllVideos(allMovies) {
  const videos = allMovies.map(({_, videos}) => videos) |> flatten();
  return videos;
}

function extractDisplayProperties(allVideos) {
  allVideos.map(({id, title, boxarts}) => {
    boxartUrl = boxarts.find(({width}) => width == 150).url;
    return {id, title, boxart: boxartUrl};
  });
}

async function getMovieDisplayProperties(endpoint) {
  return endpoint
  |> await getAllMovies
  |> flatMapAllVideos
  |> extractDisplayProperties
}