VersionGuard

A gem-style version checker for Ruby.

VersionGuard.check '2.13.0', '>= 2.2' # => true

VersionGuard has two methods: abort and check. While abort terminates the process if the version requirement is not satisfied, check just returns true / false so that you can choose what to do with the failed version.

For instance, suppose you have the following lines in config/initializers/patches.rb for a Rails app:

VersionGuard.abort 'ActiveRecord::VERSION::STRING', '3.2.9'
# Monkey patches for ActiveRecord 3.2.9...

The ruby process terminates immediately with a warning message if the version is not 3.2.9. That way, you can prevent the monkey patch from conflicting with the newer versions of ActiveRecord.

Add this line to your application's Gemfile:

gem 'version_guard'

Since VersionGuard uses Gem::Version and Gem::Version::Requirement internally, any kind of the funky version comparisons that you use with Gemfile are supported.

The first argument can be either a version string like "1.2.3" or a name that can be converted to the constant that holds the version string. For most gems, it should be something like GemName::VERSION.

# As a simple version comparator
VersionGuard.check '2.13.0', '~> 2.2'

# For mobile app backend
if VersionGuard.check request.headers['x-ios-app-version'], '< 1.2.1'
  # Send message "Your mobile app is too old, upgrade now!"
end

# For capistrano with RVM, in deploy.rb
require 'version_guard'
VersionGuard.abort ENV['rvm_version'].split(/\s/).first, '>= 1.18.5'

# Multiple version requirements are supported
VersionGuard.abort 'MyGem::VERSION', ['> 0.9.0', '< 1.1.0']