```ruby
require_relative '../../../spec_helper'
require 'rubygems'

describe "Gem.bin_path" do
  it "finds executables of default gems, which are the only files shipped for default gems" do
    # For instance, Gem.bin_path("bundler", "bundle") is used by rails new
    Gem::Specification.each_spec([Gem::Specification.default_specifications_dir]) do |spec|
      spec.executables.each do |exe|
        path = Gem.bin_path(spec.name, exe)
        File.exist?(path).should == true
      end
    end
  end
end
```

Make the Gem.bin_path even if there is a Gemfile.lock in a parent dir
user
```ruby
require_relative '../../../spec_helper'
require 'rubygems'

describe "Gem.bin_path" do
  before :each do
    @bundle_gemfile = ENV['BUNDLE_GEMFILE']
    ENV['BUNDLE_GEMFILE'] = tmp("no-gemfile")
  end

  after :each do
    ENV['BUNDLE_GEMFILE'] = @bundle_gemfile
  end

  it "finds executables of default gems, which are the only files shipped for default gems" do
    # For instance, Gem.bin_path("bundler", "bundle") is used by rails new
    Gem::Specification.each_spec([Gem::Specification.default_specifications_dir]) do |spec|
      spec.executables.each do |exe|
        path = Gem.bin_path(spec.name, exe)
        File.exist?(path).should == true
      end
    end
  end
end
```
assistant