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Channel specs

Channel specs are marked by type: :channel or if you have set config.infer_spec_type_from_file_location! by placing them in spec/channels.

A channel spec is a thin wrapper for an ActionCable::Channel::TestCase, and includes all of the behavior and assertions that it provides, in addition to RSpec's own behavior and expectations.

It also includes helpers from ActionCable::Connection::TestCase to make it possible to test connection behavior.

Background​

Given action cable testing is available

And a file named "app/channels/chat_channel.rb" with:

class ChatChannel < ApplicationCable::Channel
  def subscribed
    reject unless params[:room_id].present?
  end

  def speak(data)
    ActionCable.server.broadcast(
      "chat_#{params[:room_id]}", text: data['message']
    )
  end

  def echo(data)
    data.delete("action")
    transmit data
  end
end

A simple passing example​

Given a file named "spec/channels/chat_channel_spec.rb" with:

require "rails_helper"

RSpec.describe ChatChannel, type: :channel do
  it "successfully subscribes" do
    subscribe room_id: 42
    expect(subscription).to be_confirmed
  end
end

When I run rspec spec/channels/chat_channel_spec.rb

Then the example should pass.

Verifying that a subscription is rejected​

Given a file named "spec/channels/chat_channel_spec.rb" with:

require "rails_helper"

RSpec.describe ChatChannel, type: :channel do
  it "rejects subscription" do
    subscribe room_id: nil
    expect(subscription).to be_rejected
  end
end

When I run rspec spec/channels/chat_channel_spec.rb

Then the example should pass.

Performing actions and checking transmissions​

Given a file named "spec/channels/chat_channel_spec.rb" with:

require "rails_helper"

RSpec.describe ChatChannel, type: :channel do
  it "successfully subscribes" do
    subscribe room_id: 42

    perform :echo, foo: 'bar'
    expect(transmissions.last).to eq('foo' => 'bar')
  end
end

When I run rspec spec/channels/chat_channel_spec.rb

Then the example should pass.

A successful connection with url params​

Given a file named "app/channels/application_cable/connection.rb" with:

class ApplicationCable::Connection < ActionCable::Connection::Base
  identified_by :user_id

  def connect
    self.user_id = request.params[:user_id]
    reject_unauthorized_connection unless user_id.present?
  end
end

And a file named "spec/channels/connection_spec.rb" with:

require "rails_helper"

RSpec.describe ApplicationCable::Connection, type: :channel do
  it "successfully connects" do
    connect "/cable?user_id=323"
    expect(connection.user_id).to eq "323"
  end
end

When I run rspec spec/channels/connection_spec.rb

Then the example should pass.

A successful connection with cookies​

Given a file named "app/channels/application_cable/connection.rb" with:

class ApplicationCable::Connection < ActionCable::Connection::Base
  identified_by :user_id

  def connect
    self.user_id = cookies.signed[:user_id]
    reject_unauthorized_connection unless user_id.present?
  end
end

And a file named "spec/channels/connection_spec.rb" with:

require "rails_helper"

RSpec.describe ApplicationCable::Connection, type: :channel do
  it "successfully connects" do
    cookies.signed[:user_id] = "324"

    connect "/cable"
    expect(connection.user_id).to eq "324"
  end
end

When I run rspec spec/channels/connection_spec.rb

Then the example should pass.

A successful connection with headers​

Given a file named "app/channels/application_cable/connection.rb" with:

class ApplicationCable::Connection < ActionCable::Connection::Base
  identified_by :user_id

  def connect
    self.user_id = request.headers["x-user-id"]
    reject_unauthorized_connection unless user_id.present?
  end
end

And a file named "spec/channels/connection_spec.rb" with:

require "rails_helper"

RSpec.describe ApplicationCable::Connection, type: :channel do
  it "successfully connects" do
    connect "/cable", headers: { "X-USER-ID" => "325" }
    expect(connection.user_id).to eq "325"
  end
end

When I run rspec spec/channels/connection_spec.rb

Then the example should pass.

A rejected connection​

Given a file named "app/channels/application_cable/connection.rb" with:

class ApplicationCable::Connection < ActionCable::Connection::Base
  identified_by :user_id

  def connect
    self.user_id = request.params[:user_id]
    reject_unauthorized_connection unless user_id.present?
  end
end

And a file named "spec/channels/connection_spec.rb" with:

require "rails_helper"

RSpec.describe ApplicationCable::Connection, type: :channel do
  it "rejects connection" do
    expect { connect "/cable?user_id=" }.to have_rejected_connection
  end
end

When I run rspec spec/channels/connection_spec.rb

Then the example should pass.

Disconnect a connection​

Given a file named "app/channels/application_cable/connection.rb" with:

class ApplicationCable::Connection < ActionCable::Connection::Base
  identified_by :user_id

  def connect
    self.user_id = request.params[:user_id]
    reject_unauthorized_connection unless user_id.present?
  end

  def disconnect
    $stdout.puts "User #{user_id} disconnected"
  end
end

And a file named "spec/channels/connection_spec.rb" with:

require "rails_helper"

RSpec.describe ApplicationCable::Connection, type: :channel do
  it "disconnects" do
    connect "/cable?user_id=42"
    expect { disconnect }.to output(/User 42 disconnected/).to_stdout
  end
end

When I run rspec spec/channels/connection_spec.rb

Then the example should pass.