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Thank you for the unit-tests, that is a great step. Think the unit-test should also show that updating the NLog-Config-Variable and calling logFactory.ReconfigureExistingLoggers() will have effect on the active finalMinLevel. Which probably requires some help from ILoggingRuleLevelFilter (Just like for levels + minlevel + maxlevel)

Okay, so just to be clear: I add a new property to ILoggingRuleLevelFilter, update its implementations to handle this, and pass finalMinLevel to EnableLoggingForLevels, EnableLoggingForLevelLayout and EnableLoggingForLevelsLayout?

In my first try, I implemented a new ILoggingRuleLevelFilter and set it during parsing of finalMinLevel, but it just got cleared after EnableLevelsForRule was called. I think it misunderstood it then.

What do you think of something like this?

Also, the unit test FinalMinLevelTest seems to be failing. But given this rule:

<logger name='RequestLogger' minLevel='Debug' finalMinLevel='Error' writeTo='requestTarget' />

Shouldn't the following log be ignored, since it is below Error from finalMinLevel?

requestLogger.Debug("Debug Noise");

I will add more tests if you agree with this approach.

Like the direction where LoggingRule FinalMinLevel-property now is implemented using _logLevelFilter.

Think you should merge FinalMinLogLevelLayoutFilter into DynamicLogLevelFilter and DynamicRangeLevelFilter, so you can use any combination of these:

• Level / Levels comes from dynamic NLog Layout
• FinalMinLevel comes from dynamic NLog Layout
• MaxLevel comes from dynamic NLog Layout (range)
• MinLevel comes from dynamic NLog Layout (range)

Shouldn't the following log be ignored, since it is below Error from finalMinLevel?

Lets say you have an application that depends on a special sub-module, and you want to have a dedicated log-target for that sub-module, but at the same time you would like all errors to flow to the catch-all log-target (but not info/warn):

<logger name='RequestLogger' minLevel='Debug' writeTo='requestTarget' finalMinLevel='Error' />
<logger name='*' minLevel='Info' writeTo='catchAllTarget' />

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

91.7% Coverage
0.0% Duplication

Sorry about the many small commits to your pull-request-branch. But it now looks like the pull-request is making FinalMinLevel work with NLog Layout.

Will squash the commits, and starting working on getting NLog v5.1.3 released.

Thanks for the unit-tests and pushing for getting this included.

Hooray your first pull request is merged! Thanks for the contribution! Looking for more? 👼 Please check the up-for-grabs issues - thanks!

Sorry for the late reply, last days were busy. Thanks @snakefoot!