[Sample] accessing /about triggers checkAuth

index.js

const Koa = require('koa');
const Router = require('@koa/router');

function createRouter(prefix) {
  return new Router({
    prefix
  });
}

function routeHandler(x) { 
  return async ctx => {
    console.log(x);
    ctx.body = `${x}`;
  }
}

async function checkAuth(ctx, next) {
  console.log('checkAuth');
  // if (ctx.query['auth'] != "1") {
  //   throw new Error("not authed");
  // }
  await next();
}

function createAjaxRouter() {
  // match for '/a(.*)'
  const router = createRouter('/a');
  router.use(checkAuth);
  router.get('/1', routeHandler(1))
  return router.routes();
}

function createIndexRouter() {
  // match for '(.*)'
  const router = createRouter();
  router.get('/', routeHandler('index'));
  router.get('/about', routeHandler('about'));
  return router.routes();
}

function setRouter(app) {
  // match for '(.*)'
  const router = createRouter();
  router.use(createAjaxRouter());
  router.use(createIndexRouter());

  // order of path in routes.router.stack =>
  // ['/a(.*)', '/a/1', '/', '/about']
  const routes = router.routes();
  app.use(router.routes());
  app.use(router.allowedMethods());
}

const app = new Koa();
setRouter(app);
app.listen(3010);