Why is this gem not adding rake tasks to a Rails app?

Question

We have a gem which runs via a Rake task. The task is defined in lib/tasks/<namespace>.rake. After reading Rake tasks inside gem not being found I confirmed that the .gemspec includes the file defining the task; there is also a railtie which should be including the tasks as suggested in including rake tasks in gems. And yet our Rails 4.1 application doesn't seem to load the Rake task.

What am I missing?

Matouš Borák Matouš Borák · Accepted Answer · 2016-03-16T20:36:32

I just successfully tested your gem and I can see no problem with the rake tasks in it:

I added gem_fresh to the Gemfile and ran bundle, the gem installed
Immediately I could see the rake present in the list of rakes:
```
$ rake -T outdated
rake gem_fresh:outdated  # outdated
```

Then I updated the railtie.rb file to use the load method to load the rake defined in lib/task/metrics.rake and searched the available rakes again:

# lib/gem_fresh/railtie.rb:
rake_tasks do
  namespace :gem_fresh do
    desc "outdated"
    task :outdated => :environment do
      GemFresh::Reporter.new.report
    end
  end

  load "tasks/metrics.rake"
end 

$ rake -T outdated
rake gem_fresh:outdated     # outdated
rake metrics:outdated_gems  # display outdated gem version metrics

So, I can see no problem with your gem. Both methods in railtie (inline rake as well as using the load method) seem to work OK. The only difference I noticed is that I tested this on rails 4.2 but I rather doubt that would make a difference.

Did you put the gem into your Gemfile? If I remove it from there, I indeed see no gem_fresh rakes defined.

Why is this gem not adding rake tasks to a Rails app?

3 Answers