- instance_eval(
-   File.read('Gemfile')
- )
+ eval_gemfile('Gemfile')

ref. eval_gemfile

eval_gemfile in Ruby LSP

Ruby LSP が生成する Gemfile でもeval_gemfile が使われている。

.ruby-lsp/Gemfile の内容。

# This custom gemfile is automatically generated by the Ruby LSP.
# It should be automatically git ignored, but in any case: do not commit it to your repository.

eval_gemfile(File.expand_path("../Gemfile", __dir__))
gem "ruby-lsp", require: false, group: :development
gem "debug", require: false, group: :development, platforms: :mri
gem "ruby-lsp-rails", require: false, group: :development

dependencies in Gemfile

Gemfile 内で依存性をイジりたい場合は、dependencies を使うのが便利。

# Gemfile
#=> [Gem::Dependency.new("rails", Gem::Requirement.new(["="]), :runtime)]
# 依存性をイジる
# dependencies.delete_if