Activestorage fixtures attachments

This is far easier than anybody is making it out to be. I don't mean to demean anybody, as it took me some time to figure this out based on these answers. I'm going to use the same data model to make it easy.

User has one attached "avatar". Let's say you have this users fixture:

# users.ymlfred:  name: Fred

Here's all you need to do:

% mkdir test/fixtures/active_storage

Now, you just put "attachments.yml" and "blobs.yml" in that directory. The "attachment" record will reference the blob as well as the user:

# active_storage/attachments.ymlfreds_picture:  name: avatar  record: fred (User)  blob: freds_picture_blob

and

# active_storage/blobs.ymlfreds_picture_blob:  key: aabbWNGW1VrxZ8Eu4zmyw13A  filename: fred.jpg  content_type: image/jpeg  metadata: '{"identified":true,"analyzed":true}'  byte_size: 1000  checksum: fdUivZUf74Y6pjAiemuvlg==  service_name: local

The key is generated like this in code:

ActiveStorage::Blob.generate_unique_secure_token

You can run that in the console to get a key for the above fixture.

Now, that will "work" to have an attached picture. If you need the actual file to be there, first look in config/storage.yml to see what path the files are stored in. By default, it's "tmp/storage". The file above will be stored here:

tmp/storage/aa/bb/aabbWNGW1VrxZ8Eu4zmyw13A

To calculate the checksum, see here:

How is the checksum calculated in the blobs table for rails ActiveStorage

md5_checksum = Digest::MD5.file('tmp/storage/aa/bb/aabbWNGW1VrxZ8Eu4zmyw13A').base64digest

It would be possible to fill in the file size and checksum using erb in the fixture:

  byte_size: <%= File.size('tmp/storage/aa/bb/aabbWNGW1VrxZ8Eu4zmyw13A') %>  checksum: <%= Digest::MD5.file('tmp/storage/aa/bb/aabbWNGW1VrxZ8Eu4zmyw13A').base64digest %>

Note that you have to copy the file into the storage directory first.The storage root directory for the test environment is tmp/storage/ by default, with the remaining path constructed from the first four characters of the key (i.e. tmp/storage/aa/bb).

Lets say you have a test for the model user, the default UserTest#test_the_truth

rails test test/models/user_test.rb

I suppose you are getting an errorErrno::ENOENT: No such file or directory @ rb_sysopenduring the test, because of an error in your path,you must add 'fixtures', it should be like:

# users.ymlone:  name: 'Jim Kirk'  avatar: <%= File.open Rails.root.join('test', 'fixtures', 'files', 'image.png').to_s %>

but now you should have this error: ActiveRecord::Fixture::FixtureError: table "users" has no column named "avatar".

That's correct, because ActiveStorage uses two tables to work: active_storage_attachments and active_storage_blobs.

So, you need to remove avatar column from users.yml and add two new files:

(Disclaimer See also comments below: "no need create own models, so instead of ActiveStorageAttachment you could use original ActiveStorage::Attachment and place fixture under active_storage folder" and refer also to https://stackoverflow.com/a/55835955/5239030)

# active_storage_attachments.ymlone:  name: 'avatar'  record_type: 'User'  record_id: 1  blob_id: 1

and

# active_storage_blobs.ymlone:  id: 1  key: '12345678'  filename: 'file.png'  content_type: 'image/png'  metadata: nil  byte_size: 2000  checksum: "123456789012345678901234"

Also, in App/models, add, even if not required for the ActiveStorage to work.

# active_storage_attachment.rbclass ActiveStorageAttachment < ApplicationRecordend

and

# active_storage_blob.rbclass ActiveStorageBlob < ApplicationRecordend

Then the UserTest#test_the_truth succeed.

But better get rid of active_storage_attachment.rb and active_storage_blob.rb and follow another way to test.

For testing if the attachment is working, better test the controller, for example adding this code in test/controllers/users_controller_test.rb:

require 'test_helper'class UserControllerTest < ActionController::TestCase  def setup    @controller = UsersController.new  end  test "create user with avatar" do    user_name = 'fake_name'    avatar_image = fixture_file_upload(Rails.root.join('test', 'fixtures', 'files', 'avatar.png'),'image/png')    post :create, params: {user: {name: user_name, avatar: avatar_image}}  endend

Check the folder tmp/storage, should be empty.

Launch the test with: rails test test/controllers/users_controller_test.rb

It should succeed, then if you check again in tmp/storage, you should find some folders and files generated by the test.

Edit after comments:If you need to test the callbacks on User model, then this should work:

# rails test test/models/user_test.rbrequire 'test_helper'class UserTest < ActiveSupport::TestCase  test "should have avatar attached" do    u = User.new    u.name = 'Jim Kirk'    file = Rails.root.join('test', 'fixtures', 'files', 'image.png')    u.avatar.attach(io: File.open(file), filename: 'image.png') # attach the avatar, remove this if it is done with the callback    assert u.valid?    assert u.avatar.attached? # checks if the avatar is attached  endend

I don't know your callback, but I hope this gives you some hint.

There's a lost comment by IS04 on the only answer that I just want to expand on.

I got stuck trying to do this for sometime and following iGian's answer did work for me. However my team reviewed my PR and asked why I was introducing new models so closely named to ActiveStorage's own models (i.e. ActiveStorage::Attachment and ActiveStorage::Blob).

It then occurred to me that all I needed to do was move the fixture from active_storage_attachments.yml to active_storage/attachments.yml.

The other part I had to figure out with extra research was how to use these fixtures with the automatically generated ids. Which I did so using ActiveRecord::FixtureSet.identify like this:

attachment_identifier:  name: "attachment_name"  record_type: "MyRecordClass"  record_id: <%= ActiveRecord::FixtureSet.identify(:my_record_identifier) %>  blob_id: <%= ActiveRecord::FixtureSet.identify(:blob) %>  created_at: <%= Time.zone.now %>