getFragmentTypes.js

const fs = require('fs')
const fetch = require('node-fetch')

const prefix = process.env.TENTACLE_SERVER_SECURE ? 'https' : 'http'
const hostname = process.env.TENTACLE_SERVER_HOST || 'localhost'
const port = process.env.TENTACLE_SERVER_PORT || 4000
const url = `${prefix}://${hostname}:${port}/`

const getSchema = function () {
  return fetch(url, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      variables: {},
      query: `
        {
          __schema {
            types {
              kind
              name
              possibleTypes {
                name
              }
            }
          }
        }
      `,
    }),
  })
    .then((result) => result.json())
    .then((result) => {
      // here we're filtering out any type information unrelated to unions or interfaces
      const filteredData = result.data.__schema.types.filter(
        (type) => type.possibleTypes !== null
      )
      result.data.__schema.types = filteredData
      fs.writeFileSync(
        './fragmentTypes.json',
        JSON.stringify(result.data),
        (err) => {
          if (err) {
            throw new Error('Error writing fragmentTypes file', err)
          }
        }
      )
    })
}

module.exports = getSchema