discourse/plugins/chat/spec/lib/endpoint_spec.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

243 lines
5.2 KiB
Ruby

# frozen_string_literal: true
RSpec.describe Chat::Endpoint do
class SuccessService
include Chat::Service::Base
end
class FailureService
include Chat::Service::Base
step :fail_step
def fail_step
fail!("error")
end
end
class FailedPolicyService
include Chat::Service::Base
policy :test
def test
false
end
end
class SuccessPolicyService
include Chat::Service::Base
policy :test
def test
true
end
end
class FailedContractService
include Chat::Service::Base
class Contract
attribute :test
validates :test, presence: true
end
contract
end
class SuccessContractService
include Chat::Service::Base
contract
end
class FailureWithModelService
include Chat::Service::Base
model :fake_model, :fetch_fake_model
private
def fetch_fake_model
nil
end
end
class SuccessWithModelService
include Chat::Service::Base
model :fake_model, :fetch_fake_model
private
def fetch_fake_model
:model_found
end
end
describe ".call(service, &block)" do
subject(:endpoint) { described_class.call(service, controller, &actions_block) }
let(:result) { controller.result }
let(:actions_block) { controller.instance_eval(actions) }
let(:service) { SuccessService }
let(:actions) { "proc {}" }
let(:controller) do
Class
.new(Chat::Api) do
def request
OpenStruct.new
end
def params
ActionController::Parameters.new
end
def guardian
end
end
.new
end
it "runs the provided service in the context of a controller" do
endpoint
expect(result).to be_a Chat::Service::Base::Context
expect(result).to be_a_success
end
context "when using the on_success action" do
let(:actions) { <<-BLOCK }
proc do
on_success { :success }
end
BLOCK
context "when the service succeeds" do
it "runs the provided block" do
expect(endpoint).to eq :success
end
end
context "when the service does not succeed" do
let(:service) { FailureService }
it "does not run the provided block" do
expect(endpoint).not_to eq :success
end
end
end
context "when using the on_failure action" do
let(:actions) { <<-BLOCK }
proc do
on_failure { :fail }
end
BLOCK
context "when the service fails" do
let(:service) { FailureService }
it "runs the provided block" do
expect(endpoint).to eq :fail
end
end
context "when the service does not fail" do
let(:service) { SuccessService }
it "does not run the provided block" do
expect(endpoint).not_to eq :fail
end
end
end
context "when using the on_failed_policy action" do
let(:actions) { <<-BLOCK }
proc do
on_failed_policy(:test) { :policy_failure }
end
BLOCK
context "when the service policy fails" do
let(:service) { FailedPolicyService }
it "runs the provided block" do
expect(endpoint).to eq :policy_failure
end
end
context "when the service policy does not fail" do
let(:service) { SuccessPolicyService }
it "does not run the provided block" do
expect(endpoint).not_to eq :policy_failure
end
end
end
context "when using the on_failed_contract action" do
let(:actions) { <<-BLOCK }
proc do
on_failed_contract { :contract_failure }
end
BLOCK
context "when the service contract fails" do
let(:service) { FailedContractService }
it "runs the provided block" do
expect(endpoint).to eq :contract_failure
end
end
context "when the service contract does not fail" do
let(:service) { SuccessContractService }
it "does not run the provided block" do
expect(endpoint).not_to eq :contract_failure
end
end
end
context "when using the on_model_not_found action" do
let(:actions) { <<-BLOCK }
->(*) do
on_model_not_found(:fake_model) { :no_model }
end
BLOCK
context "when the service failed without a model" do
let(:service) { FailureWithModelService }
it "runs the provided block" do
expect(endpoint).to eq :no_model
end
end
context "when the service does not fail with a model" do
let(:service) { SuccessWithModelService }
it "does not run the provided block" do
expect(endpoint).not_to eq :no_model
end
end
end
context "when using several actions together" do
let(:service) { FailureService }
let(:actions) { <<-BLOCK }
proc do
on_success { :success }
on_failure { :failure }
on_failed_policy { :policy_failure }
end
BLOCK
it "runs the first matching action" do
expect(endpoint).to eq :failure
end
end
end
end