fix(logger): translate warning to warning instead of warn

[dustinfarris]

Translating an erlang :warning to an elixir :warn causes custom backends that still rely on this implementation to trigger the hard deprecation on Logger.warn.

[josevalim]

@dustinfarris can you please provide steps to reproduce? Do you mean that Logger.warning with a custom backend will emit deprecation warnings?

[dustinfarris]

Yes correct. I have

Logger.warning("not authorized")

which was picked up by the custom backend in getsentry/sentry-elixir — and got a deprecation notice. We are using --warnings-as-errors which started tripping when we upgraded to 1.15.

[dustinfarris]

also i recompiled logger with this change and it made the deprecation notice go away

[josevalim]

Unfortunately your change is a breaking change, because old backends are not expected to receive :warning, only :warn. I am assuming Sentry forwards its messages to Logger and, if that's the case, it has to convert :warn to :warning by itself. Thank you!

[josevalim]

If you can pinpoint from where the log level comes from in Sentry, I will be glad to provide tips or review a PR there. But at the moment it doesn't look like an Elixir bug.

[dustinfarris]

Thanks @josevalim — this PR fixes it on sentry's end: getsentry/sentry-elixir#553