no console output with Express?

[vlindhol]

I'm a bit stumped on how to get output from pg-monitor. I initialize pg-promise and pg-monitor and then use the db connection in Express.js route handlers. However, there is no console output. An example:

const pgp = require('pg-promise');
const monitor = require('pg-monitor');
const express = require('express');

const db = pgp()({ /* connection parameters */});
monitor.attach({});

const app = express();

app.use(/* routes using db.any etc to query the database */);

app.listen(8080, () => console.log('listening on 8080'));

// outputs "listening on 8080" and then nothing, even if HTTP requests are made and DB activity occurs

Is app.listen somehow blocking the output from pg-monitor or am I missing something else? I've been reading and re-reading the docs but I can't find anything obviously wrong 😅

[vlindhol]

I should add that most of the things above happen in different source files in my real-life code, in case that somehow affects the ability of attach to... attach. I tried reading the source code of pg-monitor but can not understand what mechanism is responsible for capturing events from pg-promise.

[vitaly-t]

Monitor attaches itself to the initialization-options object that you pass into pg-promise, to inject event listeners into it, as supported by pg-promise, and do console output:

const initOptions = {};
const pgp = require('pg-promise')(initOptions);

monitor.attach(initOptions); // attaching to initialization-options object

Whereas what you are doing is attaching monitor to a meaningless empty object.

[vlindhol]

Ahaa that was the issue! Thank you! It did not occur to me that it was the initOptions reference that links the two libraries together, I thought it was just a way of passing the same options (none, in my case).

I'll make a pull request to the README.md with a suggestion for a clarification, in case someone else makes the same thinking error :)

[vitaly-t]

Resolved.

[AmebaBrain]

In a current version of readme it's still not clear that you must initialize initOptions as an object and pass it both to pg-promise and pg-monitor constructors. At least I also was using attach({}) approach )

I think a comment like "to make it work you must defince options as an object and pass it to both library constructors" will do the thing