Rake Namespace Alias - namespaces

Question

Is it possible to alias a namespace in Rake?
I like how you can alias tasks:
task :commit => :c
Would love to be able to do something like this:
namespace :git => :g

Answer 1

With
task :commit => :c
you don't define an alias, you set a prerequisite.
When you call :commit the prerequsite :c is called first.
As long as there is only one prerequsite and :commit does not contain own code, it may look like an alias, but it is not.
Knowing that, you may 'alias' your namespace, if you define a default task for your namespace and set a prerequisite for this task (and the prerequisite may be again a default task of another namespace).
But I think, there is no need of aliasing namespaces. It would be enough, if you define a default task for namepsaces and perhaps 'alias' that task.
After reading the question again I have an alternative idea, based on Is there a “method_missing” for rake tasks?:
require 'rake'
namespace :long_namespace do
task :a do |tsk|
puts "inside #{tsk.name}"
end
end
rule "" do |tsk|
aliastask = tsk.name.sub(/short:/, 'long_namespace:')
Rake.application[aliastask].invoke
end
Rake.application['short:a'].invoke
The rule defines a task_missing-rule and tries to replace the namespace (in the example it replaces 'short' with 'long_namespace').
Disadvantage: An undefined task returns no error. So you need an adapted version:
require 'rake'
namespace :long_namespace do
task :a do |tsk|
puts "inside #{tsk.name}"
end
end
rule "" do |tsk|
aliastask = tsk.name.sub(/short:/, 'long_namespace:')
if Rake.application.tasks.map{|tsk| tsk.name }.include?( aliastask )
Rake.application[aliastask].invoke
else
raise RuntimeError, "Don't know how to build task '#{tsk.name}'"
end
end
Rake.application['short:a'].invoke
Rake.application['short:undefined'].invoke
And a more generalized version with a new method aliasnamespace to define the alias-namespaces:
require 'rake'
#Extend rake by aliases for namespaces
module Rake
ALIASNAMESPACES = {}
end
def aliasnamespace(alias_ns, original_ns)
Rake::ALIASNAMESPACES[alias_ns] = original_ns
end
rule "" do |tsk|
undefined = true
Rake::ALIASNAMESPACES.each{|aliasname, origin|
aliastask = tsk.name.sub(/#{aliasname}:/, "#{origin}:")
if Rake.application.tasks.map{|tsk| tsk.name }.include?( aliastask )
Rake.application[aliastask].invoke
undefined = false
end
}
raise RuntimeError, "Don't know how to build task '#{tsk.name}'" if undefined
end
#And now the usage:
namespace :long_namespace do
task :a do |tsk|
puts "inside #{tsk.name}"
end
end
aliasnamespace :short, 'long_namespace'
Rake.application['short:a'].invoke
#~ Rake.application['short:undefined'].invoke