`Prism::Translation::Parser` incompatibility with `Parser::Diagnostic`

[koic]

An incompatibility issue in handling Ruby warnings has been identified between the Parser gem and Prism.

Here is an example of the difference in emulation for the following warnings:

$ ruby -cwe "do_something *array"
-e:1: warning: `*' interpreted as argument prefix
Syntax OK

Below is the Gemfile common to expected and actual:

$ cat Gemfile
# frozen_string_literal: true

source "https://rubygems.org"

gem 'prism'
gem 'rubocop'

Expected Behavior

There is an expectation for a diagnostics array to return, similar to that provided by Parser gem:

$ bundle exec ruby -rprism/translation/parser/rubocop -ve "p RuboCop::AST::ProcessedSource.new('do_something *array', 3.3).diagnostics"
ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-darwin22]
[#<Parser::Diagnostic:0x000000011f05c7b8 @level=:warning, @reason=:ambiguous_prefix, @arguments={:prefix=>"*"}, @location=#<Parser::Source::Range (string) 13...14>, @highlights=[]>]

Actual Behavior

When using Prism as the backend, the diagnostics return value becomes an empty array:

$ bundle exec ruby -rprism/translation/parser/rubocop -ve "p RuboCop::AST::ProcessedSource.new('do_something *array', 80_82_73_83_77.33).diagnostics"
ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-darwin22]
[]

It is expected to return the same result as 3.3, even when the argument is 80_82_73_83_77.33.

Background

This difference in behavior was detected while I was working on the Prism integration, due to a failing test within RuboCop AST:
https://github.com/rubocop/rubocop-ast/blob/v1.30.0/spec/rubocop/ast/processed_source_spec.rb#L189-L197

[noahgibbs]

Interesting. We have some code in Translation::Parser that's clearly designed to do this. I'll see if I can figure out why it's not showing up where it should be.

[noahgibbs]

Ah, we're doing it with errors but not warnings. I'll look into this.