[FEATURE] Implement logging hook

[toddbaert]

Requirements

• Implement a logging hook as described in appendix A of the OpenFeaure spec: https://github.com/open-feature/spec/blob/main/specification/appendix-a-included-utilities.md#logging-hook
• Remove all logging from evaluation lifecycle (hot path)

Java implementation: open-feature/java-sdk#1084

[Rahilsiddique]

So what I understand is that we have to create a hook that will be used to log the messages during flag life-cycle
i.e before, after, error and finally
Hey I would like to give it a try 🤚
Thanks !

[toddbaert]

So what I understand is that we have to create a hook that will be used to log the messages during flag life-cycle i.e before, after, error and finally Hey I would like to give it a try 🤚 Thanks !

Yep - and also remove any non-debug logging in hot code-paths.

[beeme1mr]

Hi @Rahilsiddique, is this something you're still interested in working on?

[kevinmlong]

@beeme1mr / @toddbaert - I'm happy to take this issue on as my first issue. I can target a few weeks to have a PR opened for folks to take a look at.

[beeme1mr]

Thanks @kevinmlong!

[kevinmlong]

@beeme1mr / @toddbaert - trying to understand a few things when working on this issue.

It appears that DefaultLogger doesn't actually log anything when info or debug are called. Looking at the linked implementation from the Java SDK, it use debug for before and after. Pretty easy to fill out the implementation, but then this causes the a few tests to fail. What's the reasoning here for why console.info and console.debug shouldn't be used for the respective implementations in DefaultLogger?

[kevinmlong]

Looking at the spec (https://github.com/open-feature/spec/blob/main/specification/appendix-a-included-utilities.md#logging-hook) seems we should be using debug and info for these stages as well, so perhaps we should have the DefaultLogger implement these.

[beeme1mr]

console.debug is an alias for console.log in node.js. That's why we decided to no-op debug by default. In this case, debug feels like the correct log level but it would definitely be annoying to see nothing if you're using the default logger. @toddbaert @lukas-reining, would either of you have a suggestion?