jaakkos/winston-logstash — pull request #21 by drinks (2014-07-10 15:03:00+00:00)
Title: Only attempt to strip colors from defined meta properties

This surfaced for me when running mocha tests, my app logs on startup a worker id that's `undefined` in a test env -- It stands to reason that there may be other causes of `undefined`s that will prove hard for implementers to debug. In previous versions these differences failed silently, so this PR maintains that behavior.