GatsbyJS: Fetching the Graphql schema as soon as it is available and saving it into a local file in `.cache`

gatsby-node.js

const path = require('path');
const request = require('request-promise-native');
const fs = require('fs').promises;
const delay = require('delay');
const { introspectionQuery } = require('graphql/utilities/introspectionQuery');

const maxRetries = 4
exports.onPostBootstrap = () => {
  (async () => {
    let remainingRetries = maxRetries;
    while(remainingRetries > 0) {
      const delaytime = (maxRetries - remainingRetries + 1) * 1500;
      await delay(delaytime);
      try {
        const schema = await request.post({
          uri: 'http://localhost:8000/___graphql',
          body: { query: introspectionQuery },
          json: true,
        });
        try {
          await fs.writeFile(path.resolve(__dirname, './.cache/content-schema.json'), JSON.stringify(schema));
        } catch(e) {
          console.error('Schema writing failed:', e.message);
        }
        return;
      } catch(e) {
        remainingRetries--;
        if (remainingRetries <= 0) {
          console.warn("Could not fetch GraphQL Schema:", e.message);
        }
      }
    }
  })();
  // don't return a promise to run while build continues
}