This script generates the swagger spec for a given NestJS Module. It takes the app's path, version and module name as parameters, with optionals for

nest-gen-app-swagger.ts

import * as fs from 'fs';
import { NestFactory } from '@nestjs/core';
import { DocumentBuilder, SwaggerDocument, SwaggerModule } from '@nestjs/swagger';
import * as commander from 'commander';

const program = new commander.Command();
program
  .name('single-app-swagger-json-generator')
  .arguments('--app-path <app-path> --app-version <app-version>')
  .requiredOption('-a, --app-path <path>', 'path to app\'s folder')
  .requiredOption('-v, --app-version <version>', 'app\'s version')
  .option('-m, --module-name <module>', 'module name')
  .option('-n, --app-name <app-name>', 'app\'s name')
  .option('-o, --output-dir <output-dir>', 'output directory to write the swagger spec to');
program.parse(process.argv);

const outputDir = program.outputDir || '.';
const importPath = `${process.cwd()}/${program.appPath}`;

(async () => {
  const importedObject = await import(importPath);
  const appModule =
    program.moduleName ? importedObject[program.moduleName] :
      importedObject.default;
  const appName = program.appName || appModule.name;
  const swaggerBaseConfig = new DocumentBuilder()
    .setSchemes('https')
    .setTitle(`${appName} API`)
    .setDescription(`Auto-generated for app ${appName}.`)
    .addBearerAuth()
    .setVersion(program.appVersion)
    .build();

  const app = await NestFactory.create(appModule);
  const document: SwaggerDocument = SwaggerModule.createDocument(app, swaggerBaseConfig);
  fs.writeFileSync(`${outputDir}/${appName}.json`, JSON.stringify(document));
})();

Is there a good way to integrate the swagger CLI plugin as an AST transformer with something like this?

Would like to know that too

Haven't touched upon this in a few years, feel free to experiment and update everyone here...