Configurable Logging

[stevensJourney]

Overview

This adds the ability to specify a logger when creating a PowerSync database. The minimum log severity can be configured when creating a DefaultLogger.

Loggers also have the ability to specify custom LogWriters which can transport logs to custom sinks.

The implementation here declares a Swift logging interface and maps this to a Kotlin Kermit logger which is used internally.

[Copilot]

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

[simolus3]

I'm in favor of making the loggers customizable, but I'm wondering why we're adding our own interfaces here instead of e.g. using https://github.com/apple/swift-log? We have to write a bridge from Kermit to something either way, so why not something that has an existing ecosystem with plenty of writer implementations around it? Do we need features that library doesn't support?

[stevensJourney]

I'm in favor of making the loggers customizable, but I'm wondering why we're adding our own interfaces here instead of e.g. using https://github.com/apple/swift-log? We have to write a bridge from Kermit to something either way, so why not something that has an existing ecosystem with plenty of writer implementations around it? Do we need features that library doesn't support?

That's a fair point. My thinking here was to introduce a minimal interface with zero package dependencies. This keeps the core package lightweight and flexible. Users can opt for the default PrintLogger implementation or easily write adapters to integrate with their preferred logging library, including swift-log.

[simolus3]

I see 👍 In my humble opinion, using swift-log would make things easier for our users out of the box and reduce the code we have to write around defining logger APIs and printing to OSLog. But I understand the desire to not introduce dependencies either, and this approach looks good to me as well.

[simolus3]

LGTM 👍