Ruby: Accessing rake task from a gem without Rails

Question

I'm aware that Rake tasks can be defined in a number of places within a Ruby gem: - inside a Rakefile - inside `tasks/*.rake` - inside `lib/tasks/*.rake` I've read that the first two should be used when the tasks are to be executed on the gem itself. It seems the third option should be chosen when tasks are desired to be publicly available. There are many tutorials online demonstrating a variety of methods to load Rake tasks from a gem using Rails, namely by utilising `Rails::RailTie`. However, I'd like to find a way of using a dependency gem's tasks within another gem without needing Rails. Is there a simple solution to this? Would someone be kind enough to describe the proper approach, or outline what approaches would be viable? UPDATE I've tried creating a file `bin/my-gem` to make available on the system for executing Rake tasks from `my-gem`. I've put the following inside; ``` #!/usr/bin/env ruby require 'rubygems' require 'rake' task=ARGV[0] spec = Gem::Specification.find_by_nam…

Accepted Answer

I found the body of the solution here. I've modified it to support specification of tasks with arguments and added support for `cucumber`.

So..

Within your gem create `bin/my_gem`

Paste the script at bottom of this post into it. See comments for example usage.

Your `rake` tasks must be in your `Rakefile`.

Alternatively, add your tasks e.g. to `lib/tasks/*.rake` then add the following into your `Rakefile`:

```
Dir.glob('lib/tasks/*.rake').each {|r| import r}
```

Here's the secret sauce:

```
#!/usr/bin/env ruby

# Run rake tasks and cucumber features
# from my_gem once it's installed.
#
# Example:
#
#   my_gem rake some-task
#   my_gem rake some-task[args]
#   my_gem cucumber feature1 feature2
#
# Note: cucumber features have '.feature' appended automatically,
#       no need for you to do it ;)
#
# Author:: N David Brown
gem_dir = File.expand_path("..",File.dirname(__FILE__))
$LOAD_PATH.unshift gem_dir# Look in gem directory for resources first.
exec_type = ARGV[0]
if exec_type == 'rake' then
    require 'rake'
    require 'pp'
    pwd=Dir.pwd
    Dir.chdir(gem_dir) # We'll load rakefile from the gem's dir.
    Rake.application.init
    Rake.application.load_rakefile
    Dir.chdir(pwd) # Revert to original pwd for any path args passed to task.
    Rake.application.invoke_task(ARGV[1])
elsif exec_type == 'cucumber' then
    require 'cucumber'
    features = ARGV[1,].map{|feature| "#{gem_dir}/features/#{feature}.feature"}.join(' ')
    runtime = Cucumber::Runtime.new 
    runtime.load_programming_language('rb') 
    pwd=Dir.pwd
    Dir.chdir(gem_dir) # We'll load features from the gem's dir.
    Cucumber::Cli::Main.new([features]).execute!(runtime)
    Dir.chdir(pwd) # Revert to original pwd for convenience.
end
```

Bingo! :-)

Ruby: Accessing rake task from a gem without Rails

Solution

Problem

Related problems