How Do I Use Factory Girl To Generate A Paperclip Attachment?

I have model Person that has many Images, where images has a Paperclip attachment field called data, an abbreviated version displayed below:

class Person
  has_many :images
  ...
end

class Image
  has_attached_file :data
  belongs_to :person
  ...
end

Person is required to have at least one Image attached to it.

When using FactoryGirl, I have code akin to the following:

Factory.define :image do |a|
  a.data { File.new(File.join(Rails.root, 'features', 'support', 'file.png')) }
  a.association :person
end

Factory.define :person do |p|
  p.first_name 'Keyzer'
  p.last_name 'Soze'
  p.after_create do |person|
    person.assets = [Factory.build(:image, :person => person)]
  end
  # p.images {|images| [images.association(:image)]}
end

(N.B. I have also tried the code commented out above was also tried) Most of the time when I run cucumber features, I get an error akin to the following:

No such file or directory - /tmp/stream,9887,0.png (Errno::ENOENT)

...

Sometimes the tests run successfully.

Can anyone tell me what the problem is I am having here or how they use FactoryGirl and Paperclip together to achieve something like what I am trying to achieve?

I am using Rails 3.

You can use fixture_file_upload

include ActionDispatch::TestProcess in your test helper, here is an example factory:

include ActionDispatch::TestProcess

FactoryBot.define do
  factory :user do
    avatar { fixture_file_upload(Rails.root.join('spec', 'photos', 'test.png'), 'image/png') }
  end
end

In the above example, spec/photos/test.png needs to exist in your application's root directory before running your tests.

Note, that FactoryBot is a new name for FactoryGirl.

Newer FG syntax and no includes necessary

factory :user do
  avatar { File.new(Rails.root.join('app', 'assets', 'images', 'rails.png')) }
end

or, better yet,

factory :user do
  avatar { File.new("#{Rails.root}/spec/support/fixtures/image.jpg") } 
end

Desmond Bowe over at Pivotal Labs suggests avoiding fixture_file_upload due to memory leak problems. Instead, you should set the paperclip fields directly in your factory:

factory :attachment do
  supporting_documentation_file_name { 'test.pdf' }
  supporting_documentation_content_type { 'application/pdf' }
  supporting_documentation_file_size { 1024 }
  # ...
end

I've been using the code in the gist below:

Rails 2

http://gist.github.com/162881

Rails 3

https://gist.github.com/313121