[roskilli]

Modules that rely on global state for anything other than memory pooling or what have you should be avoided. It’s a lot more testable and clean to return a high level data structure that contains any of that state you would have held before globally in the module and have that be the “context” or just the parent data structure to any others that are spawned.

Global state makes thing impossible like parallel unit tests that all use another module, or changing things like “MaxConcurrency” in a way that is synchronized across goroutines that might already be calling into the third party module.

My 2c.

[barrkel]

Of course. I'm not advocating global state. It's just that most real systems have things like file systems, config files, databases, listening network sockets, etc. These are inherently non-local.