logging: Automatic wrap default for filter encoder

[francislavoie]

I was talking with @dunglas and he pointed out how awkward it is to have to configure wrap on the filter encoder because it loses the nice-to-have default behaviour of checking if stderr is a terminal to choose a default of console vs json.

Getting this to work just right was quite messy, but I think I got it working well now. I also made some adjustments that may or may not be considered breaking changes for some people, since we're changing some default behaviour for the filter encoder, and I slightly changed the logic for detecting the terminal.

• we're now checking if stderr is a terminal instead of stdout because our default writer is stderr anyway, it was kinda incorrect to be checking stdout I think
• fixed a bug where the writer wasn't considered when determining the default encoder; this meant that if a output file foo.log was configured and it was run at a terminal, it would write console logs to the file by default (but with color turned off). That's a bad default, it should be writing json to the file even when run as a terminal unless otherwise stated.
• now we're never removing color by default from the log output. What we would need to do is detect whether the terminal supports color or not, but we weren't doing that before so this is certainly not a regression, if anything it's just a gap, but it's not the end of the world. I do know some Windows users have complained when they used the legacy command prompt which didn't support unix style colors, but the new windows terminal does support it now so 🤷 I don't really care to deal with that detail right now, not a big deal
• wrap is no longer required for filter encoder, it now defaults to json when stderr is not a terminal, and console when it is a terminal
• to make this work, we now pass down the logger's writer module to the configured encoder if it has the ConfiguresFormatterDefault interface, which is called immediately after provisioning as a 2nd phase in provisioning
• the filter encoder implements that interface, and uses it to check if the writer is a terminal, switching the nested encoder to console; it also passes down the writer if the explicitly configured encoder if itself wants the writer (e.g. filter inside filter, or whatever).

[dunglas]

Thank you very much Francis! This will help improving Mercure default config.

[mholt]

Thanks for working on this! Yuck 😜

Likely to accept, but first, @dunglas Can you help me see the config difference for Mercure, before and after this change? I'm mainly curious so I can understand the impact here.

[francislavoie]

Ah right, I'll add an adapt test to show the difference.

[dunglas]

Currently: https://github.com/dunglas/mercure/pull/862/files

Hopefully, after, the same config in both files, automatically adapting to console or json depending on if run in TTY mode or not:

	log {
		format filter {
			fields {
				uri query {
					replace authorization REDACTED
				}
			}
		}
	}

[mholt]

Gotcha, so it allows you to remove the wrap line it looks like

[francislavoie]

Correct.

[francislavoie]

Added a test, ready to go IMO.

[francislavoie]

Oh lmao, @dunglas' review from last month was enough to allow it to get merged 😂 I didn't expect that a review from before he was granted collaborator status would be valid for that. Fun detail of github I guess!

[mholt]

ohhh, lol, that's fun -- so reviews are retroactive in granting merge permissions. That's neat.