census_api_get_fips_responses.js

const fs = require('fs')
const path = require('path')
const axios = require('axios')

const API_KEY = 'signupforafreeapikeyandaddithere'
const BASE_URL = 'https://api.census.gov/data/2010/dec/sf1'
const states = `${BASE_URL}?get=NAME&for=state:*&key=${API_KEY}`
const counties = `${BASE_URL}?get=NAME&for=county:*&key=${API_KEY}`

const DATA_DIR = 'data'
const API_RESPONSE_FILE_PREFIX = 'census_api_response'
const STATES_FILE = path.join(DATA_DIR, `${API_RESPONSE_FILE_PREFIX}_fips_states.json`)
const COUNTIES_FILE = path.join(DATA_DIR, `${API_RESPONSE_FILE_PREFIX}_fips_counties.json`)

const responsesExist = () => {
  let filesExist = false
  if (fs.existsSync(STATES_FILE)) {
    filesExist = true
  }
  if (fs.existsSync(COUNTIES_FILE)) {
    filesExist = true
  }
  return filesExist
}

if (!responsesExist()) {
  axios.all([
    axios.get(states),
    axios.get(counties)
  ]).then(axios.spread((statesResponse, countiesResponse) => {
    fs.writeFileSync(STATES_FILE, JSON.stringify(statesResponse.data, null, 2))
    fs.writeFileSync(COUNTIES_FILE, JSON.stringify(countiesResponse.data, null, 2))
    console.log('wrote census API responses')
  })).catch(error => console.log('Error getting census api responses', error))
} else {
  console.log(`responses already exist in ${DATA_DIR} dir:\n\t${STATES_FILE}\n\t${COUNTIES_FILE}`)
}