# The Ruby Spec Suite
The Ruby Spec Suite is a test suite for the behavior of the Ruby programming language.
It is not a standardized specification like the ISO one, and does not aim to become one.
Instead, it is a practical tool to describe and test the behavior of Ruby with code.
Every example code has a textual description, which presents several advantages:
* It is easier to understand the intent of the author
* It documents how recent versions of Ruby should behave
* It helps Ruby implementations to agree on a common behavior
The specs are written with syntax similar to RSpec 2.
They are run with MSpec, the purpose-built framework for running the Ruby Spec Suite.
For more information, see the [MSpec](http://github.com/ruby/mspec) project.
The specs describe the [language syntax](language/), the [core library](core/), the [standard library](library/), the [C API for extensions](optional/capi) and the [command line flags](command_line/).
The language specs are grouped by keyword while the core and standard library specs are grouped by class and method.
ruby/spec is known to be tested in these implementations for every commit:
* [MRI](http://rubyci.org/) on 30 platforms and 4 versions
* [JRuby](https://github.com/jruby/jruby/tree/master/spec/ruby) for both 1.7 and 9.x
ruby/spec describes the behavior of Ruby 2.2 and more recent Ruby versions.
More precisely, every latest stable MRI release [passes](https://rubyci.org/) all specs of ruby/spec
(latest 2.2.x, 2.3.x, 2.4.x, etc).
For older specs try these commits:
* Ruby 2.0.0-p647 - [Suite](https://github.com/ruby/spec/commit/245862558761d5abc676843ef74f86c9bcc8ea8d) using [MSpec](https://github.com/ruby/mspec/commit/f90efa068791064f955de7a843e96e2d7d3041c2) (may encounter 2 failures)
* Ruby 2.1.9 - [Suite](https://github.com/ruby/spec/commit/f029e65241374386077ac500add557ae65069b55) using [MSpec](https://github.com/ruby/mspec/commit/55568ea3918c6380e64db8c567d732fa5781efed)
### Running the specs
First, clone this repository:
$ git clone https://github.com/ruby/spec.git
Then move to it:
$ cd spec
$ git clone https://github.com/ruby/mspec.git ../mspec
And run the spec suite:
This will execute all the specs using the executable named `ruby` on your current PATH.
### Running Specs with a Specific Ruby Implementation
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.
$ ../mspec/bin/mspec -t /path/to/some/bin/ruby
### Running Selected Specs
To run a single spec file, pass the filename to `mspec`:
$ ../mspec/bin/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/bin/mspec core/kernel
Finally, you can also run them per group as defined in `default.mspec`.
The following command will run all language specs:
$ ../mspec/bin/mspec :language
In similar fashion, the following commands run the respective specs:
$ ../mspec/bin/mspec :core
$ ../mspec/bin/mspec :library
$ ../mspec/bin/mspec :capi
### History and RubySpec
This project was originally born from [Rubinius](https://github.com/rubinius/rubinius) tests being converted to the spec style.
These specs were later extracted to their own project, RubySpec, with a specific vision and principles.
At the end of 2014, Brian Shirai, the creator of RubySpec, decided to [end RubySpec](http://rubinius.com/2014/12/31/matz-s-ruby-developers-don-t-use-rubyspec/).
A couple months later, the different repositories were merged and [the project was revived](http://eregon.github.io/rubyspec/2015/07/29/rubyspec-is-reborn.html).
On 12 January 2016, the name was changed to "The Ruby Spec Suite" for clarity and to let the RubySpec ideology rest in peace.