Error when combining Express Router with Massive.js db call

Question

When making an async/await call to database from an express router to postgres db via massive.js instance, the correct response from db is received, but the router apparently returns before async function finishes; therefore, the test invocation returns undefined. From the console out (below), it seems clear that the async function is not waited for >_<

Is wrapping the router in order to pass the app instance causing the issue?

app.js

const app = express();
const massiveInstance = require("./db_connect");
const routes = require("./routes");

const PORT = 3001;
const server = massiveInstance.then(db => {
  // Add db into our app object
  app.set("db", db);

  app.use("/api", routes(app));

  app.listen(PORT, () => {
    console.log("Server listening on " + PORT);
  });
});

routes.js

const router = require("express").Router();
const { countRegions } = require("./db_queries");

const routes = app => {
  const db = app.get("db");

  router.get("/regions/count", async (request, response) => {
    try {
      const total = await countRegions(db);
      console.log(`There are ${total} regions.`);
      response.send(`There are ${total} regions.`);
    } catch (err) {
      console.error(err);
    }
  });

  return router;
};

module.exports = routes;

db_queries.js

const countRegions = db => {
  db.regions.count().then(total => {
    console.log(`db has ${total} count for regions`);
    return total;
  });
};

module.exports = {
  countRegions,
};

console output Server listening on 3001 There are undefined regions. db has 15 count for regions Server listening on 3001 There are undefined regions. db has 15 count for regions

Answer 1

You are not returning a promise returned by then in countRegions method. So you should add return in your code like this

const countRegions = db => {
  //here
  return db.regions.count().then(total => {
    console.log(`db has ${total} count for regions`);
    return total;
  });
};

or simply do,

return db.regions.count();