Infer the worker count for tapioca dsl

[rzane]

Motivation

I want tapioca dsl to infer the appropriate number of workers automatically.

Implementation

I noticed the CLI is setting default: 2 for the DSL command, but the other commands don't provide a default. The inference defined here never runs.

I'm assuming this is a mistake, but there could be a good reason for this hardcoded default that I'm not aware of.

Tests

It would be difficult to write a test for this functionality because we'd need to assert on the assumed number of workers in a test for the CLI. The worker count determination happens deep in the stack.

[KaanOzkan]

This was manually set to 2 after being automatic in 2a5db22. So we'll have to figure out why.

In the meantime it'd be good to have a way to set auto in the tapioca/config.yml so you can still achieve what you want but specific to your project. Feel free to open a PR that does that. Although right now I'm not sure how it'll work because Thor requires a specific type for the option: https://github.com/rails/thor/wiki/method-options. Maybe we could use a value of -1 to indicate auto 😬

[rzane]

Yes, I saw that commit, but I couldn't find any context for that decision.

If we find that defaulting to 2 is no longer necessary and merge this PR, is support for --workers -1 still desirable?

[KaanOzkan]

Vini found that it's coming from #618 which may be resolved already so we're discussing if we should merge this PR.

If we find that defaulting to 2 is no longer necessary and merge this PR, is support for --workers -1 still desirable?

Don't think so, no.