karma should write errors to stderr and return an exit code

[sylvain-hamel]

When an error occurs, karma uses log.error() to print the error. However it writes to stdout instead of stderr. Moreover, no error exist code is returned.

[josh-bradley]

@sylvain-hamel how were you thinking codes should be handled? Should the log.error() take the exit code as a parameter and write it out to the log?

[vojtajina]

Writing errors into stderr is easy, I think logger should be responsible for that. The default console logger should just use console.error for errors, which writes to stderr.

Handling the exit code is little bit more complicated. I think it should not be a responsibility of the logger - logger should just output logs. We should probably emit error event on the global emitter and listen on this event and 1/ clean up (eg. kill all launchers) 2/ call done callback (which is process.exit(code) by default, but could also be just a function in the case something is calling karma programatically)

[dignifiedquire]

Closing due to inactivity