Avoid logging error while log-level is warn

[iedmrc]

Hi,
I need to send warning messages but not error messages to a Slack channel. How can/should I achieve this? I tried to send false in formatter (as suggested here: https://github.com/winstonjs/winston#filtering-info-objects) but it throws:

(node:11417) UnhandledPromiseRejectionWarning: Error: Request failed with status code 400

Thanks!

[TheAppleFreak]

Hmm, that's interesting. I'll check to see if there's something that this module needs to do that I'm not doing. Sorry for the inconvenience!

[daxadal]

I encountered the same casuistry, so I suggest a custom solution. The following functionalities have been added:

• SlackHookOptions formatter can return false to filter out messages
• SlackHookOptions formatter types updated
• New test configuring SlackHook with a custom formatter that changes the output
• New test configuring SlackHook with a custom formatter that filters out the message

Pull request: #14

[TheAppleFreak]

@_@

Sorry about the delay, life got weird for me! Merged #14, so this should be resolved now.