lodash/fp + mapValues + toResponseBy = toMovie

toResponseBy.js

import _ from 'lodash/fp'

const response = {
  "Title": "Pulp Fiction",
  "Year": "1994",
  "Rated": "R",
  "Released": "14 Oct 1994",
  "Runtime": "154 min",
  "Genre": "Crime, Drama",
  "Director": "Quentin Tarantino",
  "Writer": "Quentin Tarantino (stories), Roger Avary (stories), Quentin Tarantino",
  "Actors": "Tim Roth, Amanda Plummer, Laura Lovelace, John Travolta",
  "Plot": "The lives of two mob hitmen, a boxer, a gangster's wife, and a pair of diner bandits intertwine in four tales of violence and redemption.",
  "Language": "English, Spanish, French",
  "Country": "USA",
  "Awards": "Won 1 Oscar. Another 60 wins & 68 nominations.",
  "Poster": "https://images-na.ssl-images-amazon.com/images/M/MV5BMTkxMTA5OTAzMl5BMl5BanBnXkFtZTgwNjA5MDc3NjE@._V1_SX300.jpg",
  "Ratings": [
    {
    "Source": "Internet Movie Database",
    "Value": "8.9/10"
    },
    {
    "Source": "Rotten Tomatoes",
    "Value": "94%"
    },
    {
    "Source": "Metacritic",
    "Value": "94/100"
    }
  ],
  "Metascore": "94",
  "imdbRating": "8.9",
  "imdbVotes": "1,501,400",
  "imdbID": "tt0110912",
  "Type": "movie",
  "DVD": "19 May 1998",
  "BoxOffice": "N/A",
  "Production": "Miramax Films",
  "Website": "N/A",
  "Response": "True",
}

const mapValues = transformation => (
  _.pipe(
    _.toPairs,
    _.map(([key, value]) => [key, transformation(value, key)]),
    _.fromPairs,
  )
)

const toResponseBy = ({ mappings, keys }) => {
  const allKeys = [..._.keys(mappings), ...keys];

  return _.flow(
    _.mapKeys(_.camelCase),
    _.pick(allKeys),
    mapValues((value, key) => {
      const transformation = mappings[key] || _.identity;
      return transformation(value);
    }),
  );
};

const toMovie = toResponseBy({
  mappings: {
    year: Number,
    imdbRating: Number,
    actors: _.split(', '),
    genre: _.split(', '),
  },
  keys: [
    'title',
    'director',
    'type',
  ],
});

console.log(toMovie(response))