gen_sdl.ts

/* eslint-disable no-console */
import { NestFactory } from '@nestjs/core';
import {
  GraphQLSchemaBuilderModule,
  GraphQLSchemaFactory,
} from '@nestjs/graphql';
import { printSchema } from 'graphql';
import fs from 'fs/promises';
import f from 'fs';
import path from 'path';
import { exit } from 'process';
import { glob } from 'glob';
import chalk from 'chalk';
import { INestApplication } from '@nestjs/common';
import ora from 'ora';

async function generateSchema() {
  const p = ora('generating schema...').start();
  let app: INestApplication;
  app = await NestFactory.create(GraphQLSchemaBuilderModule, {
    logger: false,
  });
  //console.log(chalk.bold.blueBright('initializing app...'));

  await app.init();

  const gqlSchemaFactory = app.get(GraphQLSchemaFactory);
  const gqlPath = 'schema/schema.gql';
  p.succeed().start('fetching resolvers...');
  //console.log(chalk.bold.blueBright('fetching resolvers...'));
  const jsfiles = await glob('./src/**/*.resolver.ts', { absolute: true });
  const resolvers = [];
  for (let i = 0; i < jsfiles.length; ++i) {
    const mod = await import(jsfiles[i]);
    const klass = mod[Object.keys(mod)[0]];
    resolvers.push(klass);
  }

  //console.log(chalk.bold.blueBright('generating schema...'));
  const schema = await gqlSchemaFactory.create(resolvers);
  const strSchema = printSchema(schema);

  if (!f.existsSync(gqlPath)) {
    f.mkdirSync(path.dirname(gqlPath));
  }

  //console.log(chalk.bold.blueBright(`writing schema to ${gqlPath} ...`));
  await fs.writeFile(gqlPath, strSchema);

  //console.log(chalk.bold.green(`successfuly wrote schema to ${gqlPath}.`));
  app.close();
  p.succeed().info('finished').stop();
}

(async () => {
  try {
    await generateSchema();
  } catch (e) {
    console.error(chalk.bold.red(`error while generating SDL: ${e}`));
    exit(1);
  }
})();