A Gemfile line names a dependency and may include a version requirement.

Gemfile Lines

gemfile_lines.rb
gem_name = 
requirements = {
  "rack" => "~> 3.0",
  "json" => ">= 2.6",
  "minitest" => "~> 5.0"
}

requirement = requirements[gem_name]
line = "gem \"#{gem_name}\", \"#{requirement}\""
has_requirement = !requirement.nil?

puts "gem=#{gem_name}"
puts "requirement=#{requirement}"
puts "line=#{line}"
puts "has_requirement=#{has_requirement}"
gem_name = 
requirements = {
  "rack" => "~> 3.0",
  "json" => ">= 2.6",
  "minitest" => "~> 5.0"
}

requirement = requirements[gem_name]
line = "gem \"#{gem_name}\", \"#{requirement}\""
has_requirement = !requirement.nil?

puts "gem=#{gem_name}"
puts "requirement=#{requirement}"
puts "line=#{line}"
puts "has_requirement=#{has_requirement}"
gem_name = 
requirements = {
  "rack" => "~> 3.0",
  "json" => ">= 2.6",
  "minitest" => "~> 5.0"
}

requirement = requirements[gem_name]
line = "gem \"#{gem_name}\", \"#{requirement}\""
has_requirement = !requirement.nil?

puts "gem=#{gem_name}"
puts "requirement=#{requirement}"
puts "line=#{line}"
puts "has_requirement=#{has_requirement}"
gemfile line A Gemfile is Ruby code, but its dependency lines usually follow a simple readable pattern.