loopback-datasource-juggler datasource definition for setup method is missing

[andreyunugro]

Steps to reproduce

At https://github.com/strongloop/loopback-datasource-juggler/blob/master/types/datasource.d.ts,
there is no definition for method setup, which is defined at:
https://github.com/strongloop/loopback-datasource-juggler/blob/06428247ad1cc48bce82d135f795fb3eaae28b33/lib/datasource.js#L382

1. I create custom datasource class MyDataSource which extends juggler.Datasource.
2. I create method setup inside class MyDataSource .
3. I can not use: super.setup() inside method setup.

Current Behavior

When I want to use super.setup(), there will be ts error: Property 'setup' does not exists on type 'Datasource'.

Expected Behavior

No ts error when I want to use super.setup() inside setup method on my custom datasource class.

Additional information

Setup method definition:

  /**
   * Setup datasource
   * @param dsName The name of the datasource.
   * @param settings The datasource settings
   */
  setup(dsName: string, settings: Options): void;
  setup(settings: Options): void;

[marioestradarosa]

I think the setup() method your are trying to call is called inside the constructor. I think you are trying to dynamically specify parameters ? Can't see your code above but you have to options if that's what you want to achieve.

    new DataSource(yourDsname, Yoursettings)

or even more if you see the code lb4 datasource generates, the dataSourceName is a static member of the extended class from juggler.DataSource and inside the constructor there is call to super(dsConfig).

What I usually is to provide to my micro services environment variables with the connection property values such as:

const config = {
  name: 'session2',
  connector: 'mysql',
  url: '',
  host: process.env.SESSION_DB_HOST,
  port: process.env.SESSION_DB_PORT,
  user: process.env.SESSION_DB_USER,
  password: process.env.SESSION_DB_PASSWORD,
  database: process.env.SESSION_DB
};

[marioestradarosa]

@andreyunugro , here is a complete example.

import {inject, lifeCycleObserver, LifeCycleObserver, ValueOrPromise} from '@loopback/core';
import {AnyObject, juggler} from '@loopback/repository';

const config = {
  name: 'demo',
  connector: 'mysql',
  url: '',
  host: '',
  port: 3306,
  user: '',
  password: '',
  database: '',
};

function updateConfig(dsConfig: AnyObject) {
  if (process.env.DEMO_DB_HOST) {
    dsConfig.host = process.env.DEMO_DB_HOST;
    dsConfig.port = +process.env.DEMO_DB_PORT!;
    dsConfig.user = process.env.DEMO_DB_USER;
    dsConfig.password = process.env.DEMO_DB_PASS;
    dsConfig.database = process.env.DEMO_DB_NAME;
  }
  return dsConfig;
}

// Observe application's life cycle to disconnect the datasource when
// application is stopped. This allows the application to be shut down
// gracefully. The `stop()` method is inherited from `juggler.DataSource`.
// Learn more at https://loopback.io/doc/en/lb4/Life-cycle.html
@lifeCycleObserver('datasource')
export class DemoDataSource extends juggler.DataSource
  implements LifeCycleObserver {
  static dataSourceName = 'demo';
  static readonly defaultConfig = config;

  constructor(
    @inject('datasources.config.demo', {optional: true})
    dsConfig: object = config,
  ) {
    super(updateConfig(dsConfig));
  }

  /**
   * Disconnect the datasource when application is stopped. This allows the
   * application to be shut down gracefully.
   */
  stop(): ValueOrPromise<void> {
    return super.disconnect();
  }
}

[andreyunugro]

Hi @marioestradarosa,

Yes, you are correct. Method setup() is called inside the constructor. Thank you for your example.

My use case is: MongoDB Automatic Client-Side Field Level Encryption.
Routine: I need to connect to current MongoDB key vault (which need MongoDB connection), add key management service, define JSON schema, and connect again to MongoDB with autoEncryption parameter; right after the setup.
If I can use setup() method, I can add the routine just after super.setup(), and I can use promise (not promise inside constructor).

The way I can do right now is using connect() method, and I have to call connect() manually.
Something like this:

It will be great if I can use setup() method.

Thank you.

[inceserhatabdullah]

If the Redis connection suddenly breaks while the backend server is running, I naturally get an error as follows.

[ioredis] Unhandled error event: Error: connect ECONNREFUSED 127.0.0.1:6379 at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1161:16)

Is it possible to do something like just turn off/deactivate the Redis DataSource without getting this error?