mongodb config does not seem to wait for the connection to resolve

[daffl]

From @eddyystop on July 30, 2017 20:45

The relevent code in src/services/monododb.js is

  const config = app.get('mongodb');
  const promise = MongoClient.connect(config);
  app.set('mongoClient', promise);

My test apparently used a mongodb service before the connection was established. It looks like it threw because app.service(...) was undefined. It did not throw once I delayed the test with a setTimeout.

I think the main concern is that an app using mongodb may sometimes boot and sometimes not.

Copied from original issue: feathersjs-ecosystem/generator-feathers#253

[daffl]

I think adding something like

before(() => app.get('mongoClient'));

In the tests should also wait for the client to connect and run your tests reliably.

[daffl]

From @eddyystop on July 30, 2017 21:20

These are not mocha tests, rather some test apps. I think this should at least be documented as its a time sink to track down.

[daffl]

I wonder if there is a good way for the generator to wait for the connection before starting the server.

[daffl]

From @eddyystop on August 1, 2017 17:35

That is the conundrum.

One positive point is that MongoDB can only be used on the server. Can anything be done with async/await?

[daffl]

This will be addressed with #853 and #509

[AmberByte]

For everyone coming here from google, I've worked around this by using a custom event which is emitted when the setup is finished.
I'm using mongoose but it should work the same way for mongodb as well

src/mongoose.ts:

import mongoose from 'mongoose';
import { Application } from './declarations';
import logger from './logger';

export default function (app: Application) {
  mongoose.connect(
    app.get('mongodb'),
    { useCreateIndex: true, useNewUrlParser: true, useUnifiedTopology: true },
  ).then(() => {
   // This emits a event called mognoose-ready on app instance
    app.emit('mongoose-ready');
  }).catch((err) => {
    logger.error(err);
    process.exit(1);
  });

  mongoose.Promise = global.Promise;

  app.set('mongooseClient', mongoose);
}

src/app.test.ts

  beforeAll((done) => {
    // Waits for mongoose to be initialized and ready then executed tests
    app.on('mongoose-ready', () => {
      done();
    });
  });

  afterAll(() => {
      app.get('mongooseClient').disconnect();
  })