# Stubbing not working at all with dry-rails

**URL:** <https://discourse.dry-rb.org/t/stubbing-not-working-at-all-with-dry-rails/1850>\
**Category:** Support\
**Created:** [October 11, 2024, 6:50am UTC](https://discourse.dry-rb.org/t/stubbing-not-working-at-all-with-dry-rails/1850 "2024-10-11T06:50:53Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![sdhull](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.dry-rb.org/sdhull/32/991_2.png) [@sdhull](https://discourse.dry-rb.org/u/sdhull)\
**Post date:** [October 11, 2024, 6:50am UTC](https://discourse.dry-rb.org/t/stubbing-not-working-at-all-with-dry-rails/1850/1 "2024-10-11T06:50:53Z")

</div>

We’re on `dry-rails 0.7.0` and I tried adding

```auto
require "dry/container/stub"

MyApp::Container.enable_stubs!

```

To our `rails_helper` and I just get a `NoMethodError`:

```auto
Failure/Error: MyApp::Container.enable_stubs!

NoMethodError:
  undefined method `enable_stubs!' for MyApp::Container:Class
  Did you mean? enabled_plugins

```

We’re on Rails 6.0 and Ruby 3.0 and using rspec. I can just stub things with rspec native stubbing, and I’m not sure why I shouldn’t…? eg

```auto
allow(MyApp::Container).to receive(:[]).with("something").and_return(
  "stubbed value"
)

```

OK it’s a bit wordy but does the job for me for now… it would be nice if native dry.rb stubbing worked though. I imagine that if I were testing something more complicated, this approach would not work so well

---

<div class="post-metadata">

**Author:** ![alassek](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.dry-rb.org/alassek/32/314_2.png) [@alassek](https://discourse.dry-rb.org/u/alassek)\
**Post date:** [October 15, 2024, 4:50pm UTC](https://discourse.dry-rb.org/t/stubbing-not-working-at-all-with-dry-rails/1850/2 "2024-10-15T16:50:56Z")

</div>

This is because dry-rails is providing a `Dry::System::Container`, not a `Dry::Core::Container` directly. A `Dry::System` container is a wrapper that provides additional functionality on top of `Dry::Core::Container`.

Here’s how I setup container testing:

```ruby
module RSpec::Testing
  module StubHelpers
    def container_stub(key, &block)
      around :example do |example|
        MyApp::Container.stub(key, instance_exec(&block)) { example.run }
      end
    end
  end
end

require "dry/system/stubs"
MyApp::Container.enable_stubs!

RSpec.configure do |config|
  config.extend RSpec::Testing::StubHelpers
end

```

And within a spec:

```ruby
RSpec.describe "My Thing" do
  let(:something) { Thing.new }
  container_stub("my.thing") { something }
end

```

---

<div class="post-metadata">

**Author:** ![alassek](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.dry-rb.org/alassek/32/314_2.png) [@alassek](https://discourse.dry-rb.org/u/alassek)\
**Post date:** [October 18, 2024, 5:11pm UTC](https://discourse.dry-rb.org/t/stubbing-not-working-at-all-with-dry-rails/1850/3 "2024-10-18T17:11:14Z")

</div>

I also want to clarify that I don’t use stubs in all situations. If your thing under test uses autoinject dependencies, you can just pass them in as arguments:

```ruby
let(:repo) { FakeRepo.new }
subject(:thing) { Thing.new(repo:) }

```

Container stubbing is useful for _transitive_ dependencies; setting up dependencies of dependencies is where argument-passing becomes really onerous.

So I tend to use this technique for integration testing mostly.