No more console.log — Messaging.ts

[lautarodragan]

Messaging.ts has six console.log calls — two in start and the remaining four in the business-specific consumePoetTimestampsDownloaded and consumeClaimsDownloaded functions.

The logs in the start function are needed in case of unexpected failure. We can sort them out by letting the consumer of the RabbitMQ client (in our case, all our module roots) pass the callbacks instead of the client having hard-coded ones.

It could look like this:

    this.amq = new AMQ(this.configuration.rabbitmqUrl)
    this.amq.onConnectionError(error => this.logger.error({ error }))
    this.amq.onConnectionClosed(() => this.logger.error({ }, 'RabbitMQ connection unexpectedly closed'))
    await this.messaging.start()

This code will be duplicated across modules, so we may want to create a Helper file to reduce code duplication a bit.

The calls in the business-specific functions act like warnings, akin to a compiler letting one know a function is being called with the incorrect arguments.

We need to decide whether we want to simply get rid of them or implement a mechanism for the consume* functions to provide feedback about dropped messages (such as a new argument to the function, a callback; or the Messaging itself taking it).

Could look like this:

    this.messaging = new Messaging(this.configuration.rabbitmqUrl)
    this.messaging.onDroppedMessage(droppedMessage => this.logger.warning({ droppedMessage }, 'RabbitMQ message dropped'))
    await this.messaging.start()

Ideally we want to implement this one after #66 to avoid introducing more noise.