Avoid memoizing dependencies

[vinistock]

Motivation

I noticed that we were keeping the project's dependencies in memory forever, but we only need that during boot. Let's save some memory and allow the array to be garbage collected.

Implementation

I turned the array into a local variable that gets used during apply_options.

Automated Tests

Adapted our tests.

[st0012]

I think it's fine to not storing the dependencies, but do we also need to change the timing test library and typechecker are detected? To me it's quite odd that we now need to rely on apply_options to detect those attributes even though they actually don't care about the options.
IMO we can just also call gather_dependencies in initialize too and keep the same behaviour.

[vinistock]

Why do you find it odd? To me it's a bit more organized to have default values in the initialize and then all automatic detection happens once we apply user options.

[st0012]

I'd expect apply_options to only change attributes that rely on options, which is the current behaviour.
In a way, it seems to blur the boundary between GlobalState#initialize and GlobalState#apply_options as I can only assume GlobalState is fully initialized after we called apply_opitons on it. I think this is clearly demonstrated by the test changes:

state = GlobalState.new
state.apply_options({})
assert_equal("rails", state.test_library)

[vinistock]

This ends up being a consequence of Sorbet. It's not possible to have non-nilable instance variables without putting them in the initializer, but we are not able to fully initialize the GlobalState until we receive the LSP's initialize request.

Ideally, we would do something like this

def run_initialize(message)
  @global_state = GlobalState.new(message)
end

But there's no way to get proper typing that way. Even if we duplicate the dependencies array and move the test framework and type checker detection inside initialize, the problem you describe isn't solved. The global state is still only fully initialized once you invoke apply_options.

It just wouldn't impact those specific tests, but conceptually, the global state is never fully initialized until the user options are applied.