Running Rake

Defining Tasks

Default Task

task :default => :target

Dependencies/Pre-requisites

task :target => :dependency
task :target => [:dependency1, :dependency2]

Defining Task Execution

task :target [=> :dependency] do (|taskObject|)
    ... stuff ...
    ... taskObject.investigation ...
end

Describing a Task

desc "Describes what the upcoming task will do"
task :target ... 

Adding to an Existing Task

task :target => :depend1

task :target => :depend2 

task :target => do
    ...
end

Files and Directories

File Lists

Works on files that exist on the system already.
FileList['data/**/*', 'out/file.txt'].exclude('*.bak')
FileList[...].exclude { |path| path =~ /ignore/ }

Create a Directory

directory 'parent/child'
task :target => 'parent/child'

rake 'parent/child' or rake target

Copy a File Task

file 'path/target.txt' => 'path/source.txt' do
    cp 'path/source.txt', 'path/target.txt' [, :verbose => true]
end
task :target => 'path/target.txt'

rake 'path/target.txt' or rake target

FileList['data/*'].each do |source|
    target = source.sub('.data', '.out')
    file target => source do
        cp source, target, :verbose => true
    end
    desc "copies all data files"
    task :copy_data_files => target
end

rake copy_data_files

File Path Manipulation

[Rake String Extensions]

Including More Tasks

Custom Task Generators

In get-pastie.rb:

require 'rake/tasklib'

# Retrieve the Pastie text for Greg's Rake quick reference.
class GetPastie < Rake::TaskLib
    attr_accessor :name, :id, :target

    # initialize sets the name and calls a block to get
    #   the rest of the options
    def initialize( name=:get_pastie )
        @name = name
        yield self if block_given?
        define
    end

    # define creates the new task(s)
    def define
        raise "id must be defined" if @id.nil?
        raise "target must be defined" if @target.nil?
        require 'open-uri'
        desc "download http://pastie.org/pastes/#{@id} to #{target}"
        task @name do
            open(@target,"w").write(open("http://pastie.org/pastes/#{@id}/download").read)
        end
    end
end

In Rakefile:

require 'get-pastie.rb'
GetPastie.new do |t|
    t.id = 239387 # the first quick ref published
    t.target = 'out/pastie_239387.rb'
end
# Name the task explicitly
GetPastie.new(:get_latest_pastie) do |t|
    t.id = 242691  # most recent as of 2008 Dec 28
    t.target = 'out/rake-quick-ref.rb'
end

Commands: rake get_pastie and rake get_latest_pastie

Clean and Clobber Tasks

require 'rake/clean'

CLEAN.add 'file-or-directory-to-delete'
CLEAN.include 'glob'
CLEAN.exclude 'dont-remove-this'

CLOBBER.add 'really-clean-this'

Commands: rake clean or rake clobber

RDoc Tasks

[RDocTask]

require 'rake/rdoctask'
Rake::RDocTask.new do |rd|
  rd.main = "README.rdoc"
  rd.rdoc_files.include("README.rdoc", "lib/**/*.rb")
end

Commands: rake rdoc or rake clobber_rdoc or rake rerdoc

Unit Test Tasks

[TestTask]

require 'rake/testtask'
Rake::TestTask.new do |t|
    t.libs << "test"
    t.test_files = FileList['test/test*.rb']
    t.verbose = true
end

Commands: rake test

Gem Tasks

[GemPackageTask] [Gem Specification Reference]

require 'rubygems'
spec = Gem::Specification.new do |s|
    s.name = 'mygem'
    s.version = '0.1'
    # ...etc ...
end

require 'rake/gempackagetask'
Rake::GemPackageTask.new(spec) do |package|
    package.need_zip = true
    package.need_tar = true
end

require 'rake/clean'
CLEAN.include('pkg')

Commands: rake package