Add action cable adapter

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## master
 
+- Add ActionCable adapter. ([@arthurWD][])
+
 ## 1.0.1 (2023-12-01) ❄️
 
 - Fix Rails 7.0 support. ([@palkan][])

README.md

@@ -165,6 +165,7 @@ Isolator has a bunch of built-in adapters:
 - `:sucker_punch`
 - `:mailer`
 - `:webmock` – track mocked HTTP requests (unseen by Sniffer) in tests
+- `:action_cable`
 
 You can dynamically enable/disable adapters, e.g.:
 

lib/isolator/adapters.rb

@@ -3,4 +3,5 @@
 require "isolator/adapters/http"
 require "isolator/adapters/background_jobs"
 require "isolator/adapters/mailers"
+require "isolator/adapters/websockets"
 require "isolator/adapters/after_commit" if defined?(::TestAfterCommit)

lib/isolator/adapters/websockets.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+if defined?(ActiveSupport)
+  ActiveSupport.on_load(:action_cable) do
+    require "isolator/adapters/websockets/action_cable"
+  end
+end

lib/isolator/adapters/websockets/action_cable.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+Isolator.isolate :action_cable,
+  target: ActionCable::Server::Base,
+  method_name: :broadcast,
+  exception_class: Isolator::WebsocketError,
+  details_message: ->(_obj, args) {
+    channel = args.first
+
+    "Broadcasting to #{channel}"
+  }

lib/isolator/errors.rb

@@ -22,4 +22,8 @@ class BackgroundJobError < UnsafeOperationError
   class MailerError < UnsafeOperationError
     MESSAGE = "You are trying to send email inside db transaction."
   end
+
+  class WebsocketError < UnsafeOperationError
+    MESSAGE = "You are trying to broadcast to a websocket connection inside db transaction. "
+  end
 end

spec/isolator/adapters/websockets/action_cable_spec.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe "ActionCable adapter" do
+  before do
+    allow(Isolator).to receive(:within_transaction?) { true }
+  end
+
+  describe "#broadcast" do
+    specify do
+      expect { ActionCable::Server::Base.new.broadcast("channel", "message") }.to raise_error(Isolator::WebsocketError, /channel/)
+    end
+  end
+end

spec/support/rails_app.rb

@@ -2,6 +2,7 @@
 
 require "rails"
 require "action_controller/railtie"
+require "action_cable"
 
 require "isolator"