RubySpec is an executable specification for the Ruby programming language. The specs describe Ruby language syntax as well as the core and standard library classes. See http://rubyspec.org for more information. The RubySpec files are written using RSpec-compatible syntax. MSpec is a purpose-built framework for running RubySpec. For more information, see the http://github.com/rubyspec/mspec project. 1. Installing MSpec The easiest way to run the RubySpecs suite is to install the MSpec gem. $ [sudo] gem install mspec Once the gem is installed, the 'mspec' executable will be available and all the commands shown below should run. However, RubySpec often utilizes the latest MSpec features, so you may want to use MSpec directly from the Git repository. $ cd /somewhere $ git clone git://github.com/rubyspec/mspec.git MSpec is now available in '/somewhere/mspec'. To make the MSpec scripts available, add the MSpec 'bin' directory to you PATH: $ export PATH=/somewhere/mspec/bin:$PATH Once you have MSpec installed, clone the RubySpec Git repository to run the specs. $ cd /somewhere $ git clone git://github.com/rubyspec/rubyspec.git To run the RubySpec suite: $ cd /somewhere/rubyspec $ mspec This will execute all the RubySpec specs using the executable named 'ruby' on your current PATH. 2. Running Specs with a Specific Ruby Interpreter Use the '-t' option to specify the Ruby implementation with which to run the specs. The argument may be a full path to the Ruby binary. For example, to run RubySpec against '/opt/ruby-enterprise/bin/ruby': $ mspec -t /opt/ruby-enterprise/bin/ruby There are some arguments that are abbreviations for known Ruby implementations. For example, if you specify 'j', then MSpec will look for 'jruby' in PATH and run RubySpec against that: $ mspec -t j See 'mspec --help' for a list of '-t' abbreviations. 3. Running Selected Specs To run a single spec file, pass the filename to 'mspec': $ mspec core/kernel/kind_of_spec.rb You can also pass a directory, in which case all specs in that directories will be run: $ mspec core/kernel Note however that passing a directory to MSpec may not always be a good idea, because some specs are language version specific. While there are version guards in the specs for version-specific behaviors, some classes and libraries are only for one Ruby version. RubySpec provides configuration files that include or exclude some spec directories based on language version. MSpec provides an option to run these sets of specs. The sets are divided by the natural divisions in RubySpec. The following command will run all core library specs specific to the language version: $ mspec :core In similar fashion, the following commands run the respective specs: $ mspec :library $ mspec :language