Ruby rake

rake is a make like tool for ruby.

Documentation

official docs	https://ruby.github.io/rake/index.html
github	https://github.com/ruby/rake
rake testtask	https://ruby.github.io/rake/Rake/TestTask.html

Tutorials

intro video

https://www.youtube.com/watch?v=AFPWDzHWjEY

Locations

project/
  rakelib/            # like conf.d, read as if in rakefile
      tags.rake
      test.rake
  lib/tasks/          # [rails only] same as rakelib
      content.rake
      db.rake
  Rakefile            # toplevel file

Usage

rake -T                  # list all rake tasks
rake -T <word>           # list rake tasks that contain '<word>'
rake -P                  # list all rake tasks, with their dependencies
rake <taskname>          # run task
rake <taskname> VAR=foo  # set environment variable within task

Basics

Rakefiles are conceptually similar to Makefiles.

• Rakefiles are composed of tasks
• Tasks can have dependencies on other tasks.

# {project}/Rakefile

# set default task, run when 'rake' invoked with no args
task :default => :mac_and_cheese

# task with dependencies
desc "Make some tasty mac & cheese"
task :mac_and_cheese => [:boil_water, :buy_pasta, :buy_cheese] do
  puts "Making mac and cheese"
end

namespace :store do
  desc "go to store"
  task :go_to_store
    puts "going to store"
  end

  desc "buy some cheese"
  task :buy_cheese
    puts "buying cheese"
  end

  desc "buy some pasta"
  task :buy_pasta
    puts "buying pasta"
  end
end

task :boil_water => [:buy_pasta, :buy_cheese]
  puts "boiling water"
end

rake                     # runs :default task
rake mac_and_cheese      # runs :mac_and_cheese
rake store:buy_cheese    # runs :buy_cheese from namespace :store

Testing

Rake provides a tool to facilitate test discovery and running.

# Rakefile

require "rake/testtask"

Rake::TestTask.new(:test) do |test|
    test.libs << "test"
    test.libs << "lib"
    test.test_files = FileList["test/**/*_test.rb"]
    test.warning = false # suppress warnings
end

task(default: :test)

You can customize it on the cli as well

# show test-files while running
bundle exec rake test TESTOPTS="-v"

Tricks

Rails

You can eager load a rails application by specifying the environment as a dependent-task.

# {project}/Rakefile

namespace :foo do
  task bar: [:environment] do
    puts MyModel.first
  end

  task :baz, [:arg1, :arg2] => [:environment] do |args|
    puts args
  end
end