Where are rake tasks defined?

Question

On a freshly created Rails project (generated by rails someName), one can run some 'default' rake tasks like:

• rake test
• rake db:migrate
• etc

Question is, where does these tasks get described? The default Rakefile doesn't have all these tasks.

Furthermore, I checked out some project that uses rspec and I am able to run rake spec to run all the tests. Where does the spec target defined?

Potluck

Does this answer your question? How do I find the source file for a rake task? – Incommensurable

Answer 1

Rake tasks are automatically loaded from the folder structure lib/tasks/*.rake

When we are talking about the task db:migrate for example, it is located within the rails gem in lib/tasks/databases.rake

So for a specific project, you will always have the tasks within the project folder structure as well as all tasks within the specified gems.

Trinitrocresol

At least in Rails 4, the database tasks are stored in the ActiveRecord gem. To see the path Rake loads a task from, use rake -W task:name – Endosperm

Answer 2

If by described you mean defined, rake -W is your friend. Example:

$ rake -W db:create

=>

rake db:create  /path/to/ruby/gems/1.9.1/gems/activerecord-3.1.11/lib/active_record/railties/databases.rake:39:in `block in <top (required)>'

Just found this out today :)

Nerin

Answer 3

To find the specific files and line numbers where a task is defined and/or modified, do this:

Start a rails console:

rails c

Then run these commands:

require 'rake'
Rake::TaskManager.record_task_metadata=true
Rake.application.load_rakefile
tsk = Rake.application.tasks.find {|t| t.name =='my_task_name'}
tsk.locations

Rake basically can track the locations internally and has a nifty method to show them upon request. The above code basically loads rake, tells Rake to track the file locations, loads the Rakefile (and all other included ones), finds the task in question, and calls the locations method on it.

From sameers comment, for rake v 10.1.0 and possibly older versions of rake you might have to call: tsk.actions instead of tsk.locations

Stocker

This is a great tip! I am working on an application with tasks defined in several different libraries, and it can be really tough to figure out what task comes from where without a trick like this. – Ryder

That might be code that works for an older version of Rake ... I have 10.1.0, in which you have to change the last line to tsk.actions – Manzanilla

@Manzanilla - Thanks for the comment. I just tried with rake-10.1.1 and it works with locations. – Stocker

I apologize - I should have said "different version of," rather than assuming it was an older one :) – Manzanilla

Thanks for the update. I will add something to the main post about it. Cheers! – Stocker

Small note: You shouldn't need that each. Rake.application.tasks.find. Also you may need to send load if it's private for you. Rake.application.send(:load, 'Rakefile') or you could just use Rake.application.load_rakefile. – Mose

@con-- Thanks for that. Updated accordingly. – Stocker

Answer 4

You didn't specify which version of rails you're using but in 3.0.7 the db tasks are located in the ActiveRecord gem in

lib/active_record/railties/databases.rake

Update:

As of rails version 3.2.7, the tasks are still where I stated above.

Hornbook

Answer 5

In Rails 3 the railties gem defines a lot of rake tasks.

railties-3.2.5/lib/rails/tasks/annotations.rake
railties-3.2.5/lib/rails/tasks/documentation.rake
railties-3.2.5/lib/rails/tasks/engine.rake
railties-3.2.5/lib/rails/tasks/framework.rake
railties-3.2.5/lib/rails/tasks/log.rake
railties-3.2.5/lib/rails/tasks/middleware.rake
railties-3.2.5/lib/rails/tasks/misc.rake
railties-3.2.5/lib/rails/tasks/routes.rake
railties-3.2.5/lib/rails/tasks/statistics.rake
railties-3.2.5/lib/rails/tasks/tmp.rake
railties-3.2.5/lib/rails/test_unit/testing.rake

If your $EDITOR is configured, you can easily see them yourself with the open_gem gem:

gem install open_gem
gem open railties

Judaism

Answer 6

To list all tasks:

rake -P

Since many tasks come from gems you install it's hard to know which ones are added...

Cassiecassil

rails --help might help show some of the tasks that rake doesn't: guides.rubyonrails.org/command_line.html#bin-rails – Internationalist

Answer 7

The project you checked out probably uses the rspec-rails gem. That gem defines the spec task. You can see the source code for it here:

https://github.com/rspec/rspec-rails/blob/master/lib/rspec/rails/tasks/rspec.rake

Sarette