Debug gem conflict with rspec mocks

Open
#1,154 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
45/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
ruby
Domain
devtools

Research direction

Start with lib/debug/source_repository.rb:38 and run the Ruby 3.3.7 reproduction from the issue with debug 1.11.0 and RSpec. Trace how the File.exist? call interacts with the configured mock. Done means the reproduction passes without mock expectation errors while preserving the source repository behavior.

Written by the indexing model from the issue text.

Description

Your environment

  • ruby -v: ruby 3.3.7
  • rdbg -v: 1.11.0

Describe the bug
The debug gem's method in debug/source_repository.rb:38 calls File.exist?, which interferes with RSpec mocks that stub this method for specific file paths. This causes test failures with mock expectation errors when the debug gem is loaded during test execution.

To Reproduce

system('gem install bundler') unless Gem::Specification::find_all_by_name('bundler').any?
require 'bundler/inline'

gemfile(true) do
  source 'https://rubygems.org'
  gem 'rspec'
  gem 'debug', '~> 1.11.0'
end

require 'rspec'
require 'debug'

class MyClass
  def check_if_file_exist?(path)
    File.exist?(path)
  end
end

RSpec.describe "debug gem + File.exist? conflict" do
  let(:target_path) { "config/session_store.yml" }

  let(:my_class) { MyClass.new }

  before do
    allow(File).to receive(:exist?).with(target_path).and_return(true)
  end

  it "stubs File.exist? and avoids debug interference" do
    result = my_class.check_if_file_exist?(target_path)

    expect(result).to be true
  end
end

RSpec::Core::Runner.run([])

Expected behavior
A clear and concise description of what you expected to happen.

  • The test should pass
Dominant language
Ruby
Stars
1.3k
Forks
146
No merged PRs in 30d

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from ruby/debug

All issues in ruby/debug

Similar issues

More Ruby issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.