JSON to Graphql schema generator

input.json

{"title":"A New Hope","episode_id":4,"opening_crawl":"It is a period of civil war.\r\nRebel spaceships, striking\r\nfrom a hidden base, have won\r\ntheir first victory against\r\nthe evil Galactic Empire.\r\n\r\nDuring the battle, Rebel\r\nspies managed to steal secret\r\nplans to the Empire's\r\nultimate weapon, the DEATH\r\nSTAR, an armored space\r\nstation with enough power\r\nto destroy an entire planet.\r\n\r\nPursued by the Empire's\r\nsinister agents, Princess\r\nLeia races home aboard her\r\nstarship, custodian of the\r\nstolen plans that can save her\r\npeople and restore\r\nfreedom to the galaxy....","director":"George Lucas","producer":"Gary Kurtz, Rick McCallum","release_date":"1977-05-25","characters":["http://swapi.co/api/people/1/","http://swapi.co/api/people/2/","http://swapi.co/api/people/3/","http://swapi.co/api/people/4/","http://swapi.co/api/people/5/","http://swapi.co/api/people/6/","http://swapi.co/api/people/7/","http://swapi.co/api/people/8/","http://swapi.co/api/people/9/","http://swapi.co/api/people/10/","http://swapi.co/api/people/12/","http://swapi.co/api/people/13/","http://swapi.co/api/people/14/","http://swapi.co/api/people/15/","http://swapi.co/api/people/16/","http://swapi.co/api/people/18/","http://swapi.co/api/people/19/","http://swapi.co/api/people/81/"],"planets":["http://swapi.co/api/planets/2/","http://swapi.co/api/planets/3/","http://swapi.co/api/planets/1/"],"starships":["http://swapi.co/api/starships/2/","http://swapi.co/api/starships/3/","http://swapi.co/api/starships/5/","http://swapi.co/api/starships/9/","http://swapi.co/api/starships/10/","http://swapi.co/api/starships/11/","http://swapi.co/api/starships/12/","http://swapi.co/api/starships/13/"],"vehicles":["http://swapi.co/api/vehicles/4/","http://swapi.co/api/vehicles/6/","http://swapi.co/api/vehicles/7/","http://swapi.co/api/vehicles/8/"],"species":["http://swapi.co/api/species/4/","http://swapi.co/api/species/5/","http://swapi.co/api/species/3/","http://swapi.co/api/species/2/","http://swapi.co/api/species/1/"],"created":"2014-12-10T14:23:31.880000Z","edited":"2015-04-11T09:46:52.774897Z","url":"http://swapi.co/api/films/1/"}

json-to-graphql.js

/*
 * Usage:
 * 1. npm install lodash
 * 2. node json-to-graphql.js <filename>
 *
 * Only support
     GraphQLObjectType
     GraphQLList
     GraphQLString
     GraphQLBoolean
     GraphQLInt
     GraphQLFloat
 * See: https://github.com/graphql/graphql-js/blob/master/src/type/index.js
 */
var _ = require('lodash')
var fs = require('fs')
var path = require('path')

var INDENT = 4
var TAB = new Array(INDENT).fill(' ').join('')
function transform(json, level, name) {
    var definition
    if (_.isArray(json)) {
        if (name.slice(-1) === 's') {
            name = name.slice(0, -1)
        } else {
            name = name + 'Item'
        }
        definition = transform(json[0], level + INDENT, name)
        if (!definition) return
        return `new GraphQLList(${definition})`
    } else if (_.isString(json)) {
        return `GraphQLString`
    } else if (_.isBoolean(json)) {
        return `GraphQLString`
    } else if (isInt(json)) {
        return `GraphQLInt`
    } else if (isFloat(json)) {
        return `GraphQLFloat`
    } else if (_.isObject(json)) {
        if (Object.keys(json).length === 0) return

        var field, value
        var spaces = new Array(level).fill(' ').join('')
        var name = name ? (name[0].toUpperCase() + name.slice(1)) : ''

        var schema = `new GraphQLObjectType({
${spaces}${TAB}name: "${name}",
${spaces}${TAB}description: "",
${spaces}${TAB}fields: () => ({`
        for (field in json) {
            value = json[field]
            definition = transform(value, level + INDENT * 2, field)
            if (!definition) continue
            schema += `
${spaces}${TAB}${TAB}"${field}": {
${spaces}${TAB}${TAB}${TAB}type: ${definition}
${spaces}${TAB}${TAB}},`
        }
        schema += `
${spaces}${TAB}})
${spaces}})`
        return schema
    }
}

// http://stackoverflow.com/questions/3885817/how-to-check-that-a-number-is-float-or-integer
function isInt(n){
    return Number(n) === n && n % 1 === 0;
}

function isFloat(n){
    return n === Number(n) && n % 1 !== 0;
}

if (process.argv.length < 3) {
    console.error(`Usage: node json-to-graphql.js <filename>`)
    process.exit(1)
}

var filename = process.argv[2]
var json = fs.readFileSync(filename, 'utf8')
json = JSON.parse(json)
var schema = transform(json, 0, path.basename(filename, path.extname(filename)))
schema = `// Auto generate by https://gist.github.com/CatTail/2ed985c5afc5b41a4e06
import {
  GraphQLInt,
  GraphQLFloat,
  GraphQLList,
  GraphQLObjectType,
  GraphQLString,
} from 'graphql'

var Type = ${schema}

export default Type
`
console.log(schema)

output.js

new GraphQLObjectType({
    name: "some name",
    description: "",
    fields: () => ({
        "title": {
            type: GraphQLString
        },
        "episode_id": {
            type: GraphQLInt
        },
        "opening_crawl": {
            type: GraphQLString
        },
        "director": {
            type: GraphQLString
        },
        "producer": {
            type: GraphQLString
        },
        "release_date": {
            type: GraphQLString
        },
        "characters": {
            type: new GraphQLList(GraphQLString)
        },
        "planets": {
            type: new GraphQLList(GraphQLString)
        },
        "starships": {
            type: new GraphQLList(GraphQLString)
        },
        "vehicles": {
            type: new GraphQLList(GraphQLString)
        },
        "species": {
            type: new GraphQLList(GraphQLString)
        },
        "created": {
            type: GraphQLString
        },
        "edited": {
            type: GraphQLString
        },
        "url": {
            type: GraphQLString
        },
    })
})