printSchemaWithDirectives.js

import { print, isSpecifiedScalarType, isSpecifiedDirective } from 'graphql';

export function printSchemaWithDirectives(schema) {
  const str = Object
    .keys(schema.getTypeMap())
    .filter(k => !k.match(/^__/))
    .reduce((accum, name) => {
      const type = schema.getType(name);
      return !isSpecifiedScalarType(type)
        ? accum += `${print(type.astNode)}\n`
        : accum;
    }, '');

  return schema
    .getDirectives()
    .reduce((accum, d) => {
      return !isSpecifiedDirective(d)
        ? accum += `${print(d.astNode)}\n`
        : accum;
    }, str + `${print(schema.astNode)}\n`);
}