discourse/plugins/chat/app/services/update_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

89 lines
2.8 KiB
Ruby

# frozen_string_literal: true
module Chat
module Service
# Service responsible for updating a chat channel's name, slug, and description.
#
# For a CategoryChannel, the settings for auto_join_users and allow_channel_wide_mentions
# are also editable.
#
# @example
# Chat::Service::UpdateChannel.call(
# channel_id: 2,
# guardian: guardian,
# name: "SuperChannel",
# description: "This is the best channel",
# slug: "super-channel",
# )
#
class UpdateChannel
include Base
# @!method call(channel_id:, guardian:, **params_to_edit)
# @param [Integer] channel_id
# @param [Guardian] guardian
# @param [Hash] params_to_edit
# @option params_to_edit [String,nil] name
# @option params_to_edit [String,nil] description
# @option params_to_edit [String,nil] slug
# @option params_to_edit [Boolean] auto_join_users Only valid for {CategoryChannel}. Whether active users
# with permission to see the category should automatically join the channel.
# @option params_to_edit [Boolean] allow_channel_wide_mentions Allow the use of @here and @all in the channel.
# @return [Chat::Service::Base::Context]
model :channel, :fetch_channel
policy :no_direct_message_channel
policy :check_channel_permission
contract default_values_from: :channel
step :update_channel
step :publish_channel_update
step :auto_join_users_if_needed
# @!visibility private
class Contract
attribute :name, :string
attribute :description, :string
attribute :slug, :string
attribute :auto_join_users, :boolean, default: false
attribute :allow_channel_wide_mentions, :boolean, default: true
before_validation do
assign_attributes(
attributes
.symbolize_keys
.slice(:name, :description, :slug)
.transform_values(&:presence),
)
end
end
private
def fetch_channel(channel_id:, **)
ChatChannel.find_by(id: channel_id)
end
def no_direct_message_channel(channel:, **)
!channel.direct_message_channel?
end
def check_channel_permission(guardian:, channel:, **)
guardian.can_preview_chat_channel?(channel) && guardian.can_edit_chat_channel?
end
def update_channel(channel:, contract:, **)
channel.update!(contract.attributes)
end
def publish_channel_update(channel:, guardian:, **)
ChatPublisher.publish_chat_channel_edit(channel, guardian.user)
end
def auto_join_users_if_needed(channel:, **)
return unless channel.auto_join_users?
Chat::ChatChannelMembershipManager.new(channel).enforce_automatic_channel_memberships
end
end
end
end