generateSchema.ts

import fs from 'fs';
import path from 'path';
import { promisify } from 'util';

import { printSchema } from 'graphql/utilities';

import schema from '@sejamelhoramigo/graphql/src/schema';

const writeFileAsync = promisify(fs.writeFile);

(async () => {
  const configs = [
    {
      schema,
      path: './',
    },
  ];

  for await (const config of configs) {
    await writeFileAsync(path.join(process.cwd(), `${config.path}/schema.graphql`), printSchema(config.schema));
  }

  process.exit(0);
})();

introspection.graphql

{
  __schema {
    directives {
      name
      description
    }
    subscriptionType {
      name
      description
    }
    types {
      name
      description
    }
    queryType {
      name
      description
    }
    mutationType {
      name
      description
    }
    queryType {
      name
      description
    }
  }
}