The class variable was leaking into other tests.
@betesh pointed out that one may be defined without the other, and the existance of both cannot be implied from the existance of the Rails module.
…ommand_without_rails Conflicts: lib/delayed/command.rb spec/delayed/command_spec.rb
Calling Delayed::Worker.new multiple times would continue to re-add the plugins to the lifecycle. Some gems and projects use the pattern `Delayed::Worker.new.work_off` to trigger delayed jobs in specs. Over time, the callback chain would get very long and, in our case, caused a StackLevelTooDeep error. Better would be to have a proper singleton: `Delayed::Worker.worker.work_off` In the absence of a proper singleton, this will make the pattern work.