discourse/plugins/chat/app/services/trash_channel.rb
Martin Brennan 60ad836313
DEV: Chat service object initial implementation (#19814)
This is a combined work of Martin Brennan, Loïc Guitaut, and Joffrey Jaffeux.

---

This commit implements a base service object when working in chat. The documentation is available at https://discourse.github.io/discourse/chat/backend/Chat/Service.html

Generating documentation has been made as part of this commit with a bigger goal in mind of generally making it easier to dive into the chat project.

Working with services generally involves 3 parts:

- The service object itself, which is a series of steps where few of them are specialized (model, transaction, policy)

```ruby
class UpdateAge
  include Chat::Service::Base

  model :user, :fetch_user
  policy :can_see_user
  contract
  step :update_age

  class Contract
    attribute :age, :integer
  end

  def fetch_user(user_id:, **)
    User.find_by(id: user_id)
  end

  def can_see_user(guardian:, **)
    guardian.can_see_user(user)
  end

  def update_age(age:, **)
    user.update!(age: age)
  end
end
```

- The `with_service` controller helper, handling success and failure of the service within a service and making easy to return proper response to it from the controller

```ruby
def update
  with_service(UpdateAge) do
    on_success { render_serialized(result.user, BasicUserSerializer, root: "user") }
  end
end
```

- Rspec matchers and steps inspector, improving the dev experience while creating specs for a service

```ruby
RSpec.describe(UpdateAge) do
  subject(:result) do
    described_class.call(guardian: guardian, user_id: user.id, age: age)
  end

  fab!(:user) { Fabricate(:user) }
  fab!(:current_user) { Fabricate(:admin) }

  let(:guardian) { Guardian.new(current_user) }
  let(:age) { 1 }

   it { expect(user.reload.age).to eq(age) }
end
```

Note in case of unexpected failure in your spec, the output will give all the relevant information:

```
  1) UpdateAge when no channel_id is given is expected to fail to find a model named 'user'
     Failure/Error: it { is_expected.to fail_to_find_a_model(:user) }

       Expected model 'foo' (key: 'result.model.user') was not found in the result object.

       [1/4] [model] 'user' 
       [2/4] [policy] 'can_see_user'
       [3/4] [contract] 'default'
       [4/4] [step] 'update_age'

       /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/update_age.rb:32:in `fetch_user': missing keyword: :user_id (ArgumentError)
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/base.rb:202:in `instance_exec'
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/base.rb:202:in `call'
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/base.rb:219:in `call'
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/base.rb:417:in `block in run!'
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/base.rb:417:in `each'
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/base.rb:417:in `run!'
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/base.rb:411:in `run'
       	from <internal:kernel>:90:in `tap'
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/app/services/base.rb:302:in `call'
       	from /Users/joffreyjaffeux/Code/pr-discourse/plugins/chat/spec/services/update_age_spec.rb:15:in `block (3 levels) in <main>'
```
2023-02-13 13:09:57 +01:00

67 lines
1.8 KiB
Ruby

# frozen_string_literal: true
module Chat
module Service
# Service responsible for trashing a chat channel.
# Note the slug is modified to prevent collisions.
#
# @example
# Chat::Service::TrashChannel.call(channel_id: 2, guardian: guardian)
#
class TrashChannel
include Base
# @!method call(channel_id:, guardian:)
# @param [Integer] channel_id
# @param [Guardian] guardian
# @return [Chat::Service::Base::Context]
DELETE_CHANNEL_LOG_KEY = "chat_channel_delete"
model :channel, :fetch_channel
policy :invalid_access
transaction do
step :prevents_slug_collision
step :soft_delete_channel
step :log_channel_deletion
end
step :enqueue_delete_channel_relations_job
private
def fetch_channel(channel_id:, **)
ChatChannel.find_by(id: channel_id)
end
def invalid_access(guardian:, channel:, **)
guardian.can_preview_chat_channel?(channel) && guardian.can_delete_chat_channel?
end
def prevents_slug_collision(channel:, **)
channel.update!(
slug:
"#{Time.current.strftime("%Y%m%d-%H%M")}-#{channel.slug}-deleted".truncate(
SiteSetting.max_topic_title_length,
omission: "",
),
)
end
def soft_delete_channel(guardian:, channel:, **)
channel.trash!(guardian.user)
end
def log_channel_deletion(guardian:, channel:, **)
StaffActionLogger.new(guardian.user).log_custom(
DELETE_CHANNEL_LOG_KEY,
{ chat_channel_id: channel.id, chat_channel_name: channel.title(guardian.user) },
)
end
def enqueue_delete_channel_relations_job(channel:, **)
Jobs.enqueue(:chat_channel_delete, chat_channel_id: channel.id)
end
end
end
end