Remove OpenStruct dependency

[dduugg]

Verification

• This issue's title and/or description do not reference a single formula e.g. brew install wget. If they do, open an issue at https://github.com/Homebrew/homebrew-core/issues/new/choose instead.

Provide a detailed description of the proposed feature

ostruct will no longer be a default gem as of Ruby 3.5: ruby/ruby#10428
It's already discouraged for "performance, version compatibility, and potential security issues".

We have two instances to clean up:

Library/Homebrew/cli/args.rb
Library/Homebrew/cmd/uses.rb

What is the motivation for the feature?

☝️

How will the feature be relevant to at least 90% of Homebrew users?

resolution of the performance, version compatibility, and potential security issues described above.

What alternatives to the feature have been considered?

None

[MikeMcQuaid]

Agreed, we should do this.

[apainintheneck]

It'd be simple to create a small class that replicates the OpenStruct usage in Homebrew::Cmd::Uses (I can do this real quick). Removing it from Homebrew::CLI::Args will be a bit more involved.

[dduugg]

Yep, the class is a single file, and must of the functionality is via an @table attr that is accessed via method_missing: https://github.com/ruby/ostruct/blob/master/lib/ostruct.rb

It still leaves the major concerns intact though (e.g. performance & security), the code remains difficult to follow, etc. Opening this so we have a bit of time to think of something better (but feel free to self-assign if you have strong opinions).

[apainintheneck]

I see your point. The goal here is not just to remove the OpenStruct dependency but also refactor the surrounding code so that it doesn't rely on OpenStruct-like anti-patterns.

[MikeMcQuaid]

The goal here is not just to remove the OpenStruct dependency but also refactor the surrounding code so that it doesn't rely on OpenStruct-like anti-patterns.

Exactly. OpenStruct is also pretty Sorbet-unfriendly.