Add `file_fixture_upload` to factories

[jmschp]

Problem this feature will solve

When defining factories that involve file uploads (e.g., Active Storage attachments or models with has_one_attached attributes), it’s convenient to use Rails’ built-in helpers for test files.

factory_bot_rails already makes the file_fixture helper available in factories, but not file_fixture_upload, which is its natural companion in Rails tests. This inconsistency makes it harder to use Rails’ native testing tools for simulating file uploads inside factories.

Desired solution

Include the file_fixture_upload helper in the methods available to FactoryBot factories (similar to how file_fixture is currently included).

This would allow factories to use upload helpers like:

factory :user do
  avatar { file_fixture_upload('avatar.png', 'image/png') }
end

without requiring additional setup in the test suite.

Alternatives considered

• Manually including ActionDispatch::TestProcess into FactoryBot::SyntaxRunner, e.g.:

  FactoryBot::SyntaxRunner.include ActionDispatch::TestProcess::FixtureFile

  While functional, this workaround feels inconsistent with the built-in inclusion of file_fixture and requires additional setup in every Rails project using factory_bot_rails.

Additional context

file_fixture_upload is a standard Rails helper that complements file_fixture, both of which are part of Rails’ test support layer. Since factory_bot_rails is already Rails-specific and includes similar helpers, adding this one would improve consistency and developer experience with minimal additional coupling.

I am more than happy to start a PR if you consider this useful.