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Class: ActionCable::Channel::TestCase

Overview

Superclass for Action Cable channel functional tests.

Basic example

Functional tests are written as follows:

  1. First, one uses the subscribe method to simulate subscription creation.

  2. Then, one asserts whether the current state is as expected. “State” can be anything: transmitted messages, subscribed streams, etc.

For example:

class ChatChannelTest < ActionCable::Channel::TestCase
  def test_subscribed_with_room_number
    # Simulate a subscription creation
    subscribe room_number: 1

    # Asserts that the subscription was successfully created
    assert subscription.confirmed?

    # Asserts that the channel subscribes connection to a stream
    assert_has_stream "chat_1"

    # Asserts that the channel subscribes connection to a specific
    # stream created for a model
    assert_has_stream_for Room.find(1)
  end

  def test_does_not_stream_with_incorrect_room_number
    subscribe room_number: -1

    # Asserts that not streams was started
    assert_no_streams
  end

  def test_does_not_subscribe_without_room_number
    subscribe

    # Asserts that the subscription was rejected
    assert subscription.rejected?
  end
end

You can also perform actions:

def test_perform_speak
  subscribe room_number: 1

  perform :speak, message: "Hello, Rails!"

  assert_equal "Hello, Rails!", transmissions.last["text"]
end

Special methods

TestCase will also automatically provide the following instance methods for use in the tests:

connection

An ActionCable::Channel::ConnectionStub, representing the current HTTP connection.

subscription

An instance of the current channel, created when you call subscribe.

transmissions

A list of all messages that have been transmitted into the channel.

Channel is automatically inferred

TestCase will automatically infer the channel under test from the test class name. If the channel cannot be inferred from the test class name, you can explicitly set it with tests.

class SpecialEdgeCaseChannelTest < ActionCable::Channel::TestCase
  tests SpecialChannel
end

Specifying connection identifiers

You need to set up your connection manually to provide values for the identifiers. To do this just use:

stub_connection(user: users(:john))

Testing broadcasting

TestCase enhances ::ActionCable::TestHelper assertions (e.g. assert_broadcasts) to handle broadcasting to models:

# in your channel
def speak(data)
  broadcast_to room, text: data["message"]
end

def test_speak
  subscribe room_id: rooms(:chat).id

  assert_broadcast_on(rooms(:chat), text: "Hello, Rails!") do
    perform :speak, message: "Hello, Rails!"
  end
end

Constant Summary

::ActiveSupport::TestCase - Inherited

Assertion

Behavior - Included

CHANNEL_IDENTIFIER

Behavior - Attributes & Methods

Class Attribute Summary

::ActiveSupport::TestCase - Inherited

.file_fixture_path, .file_fixture_path?,
.test_order

Returns the order in which test cases are run.

.test_order=

Sets the order in which test cases are run.

Class Method Summary

::ActiveSupport::TestCase - Inherited

.parallelize

Parallelizes the test suite.

.parallelize_setup

Set up hook for parallel testing.

.parallelize_teardown

Clean up hook for parallel testing.

::ActiveSupport::Testing::Declarative - Extended

test

Helper to define a test method using a ::String.

Instance Attribute Summary

Instance Method Summary

Behavior - Included

#assert_broadcast_on,
#assert_broadcasts

Enhance TestHelper assertions to handle non-String broadcastings.

#assert_has_stream

Asserts that the specified stream has been started.

#assert_has_stream_for

Asserts that the specified stream for a model has started.

#assert_no_streams

Asserts that no streams have been started.

#perform

Perform action on a channel.

#stub_connection

Set up test connection with the specified identifiers:

#subscribe

Subscribe to the channel under test.

#transmissions

Returns messages transmitted into channel.

#unsubscribe

Unsubscribe the subscription under test.

::ActionCable::TestHelper - Included

#assert_broadcast_on

Asserts that the specified message has been sent to the stream.

#assert_broadcasts

Asserts that the number of broadcasted messages to the stream matches the given number.

#assert_no_broadcasts

Asserts that no messages have been sent to the stream.

::ActiveSupport::TestCase - Inherited

::ActiveSupport::Testing::FileFixtures - Included

#file_fixture

Returns a ::Pathname to the fixture file named fixture_name.

::ActiveSupport::Testing::TimeHelpers - Included

#after_teardown,
#freeze_time

Calls travel_to with Time.now.

#travel

Changes current time to the time in the future or in the past by a given time difference by stubbing Time.now, Date.today, and DateTime.now.

#travel_back

Returns the current time back to its original state, by removing the stubs added by travel, travel_to, and freeze_time.

#travel_to

Changes current time to the given time by stubbing Time.now, Date.today, and DateTime.now to return the time or date passed into this method.

#unfreeze_time

::ActiveSupport::Testing::Assertions - Included

#assert_changes

Assertion that the result of evaluating an expression is changed before and after invoking the passed in block.

#assert_difference

Test numeric difference between the return value of an expression as a result of what is evaluated in the yielded block.

#assert_no_changes

Assertion that the result of evaluating an expression is not changed before and after invoking the passed in block.

#assert_no_difference

Assertion that the numeric result of evaluating an expression is not changed before and after invoking the passed in block.

#assert_not

Asserts that an expression is not truthy.

#assert_nothing_raised

Assertion that the block should not raise an exception.

Class Attribute Details

._channel_class (rw)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/channel/test_case.rb', line 176

class_attribute :_channel_class

._channel_class?Boolean (rw)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/channel/test_case.rb', line 176

class_attribute :_channel_class

Instance Attribute Details

#_channel_class (rw)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/channel/test_case.rb', line 176

class_attribute :_channel_class

#_channel_class?Boolean (rw)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/channel/test_case.rb', line 176

class_attribute :_channel_class

#connection (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/channel/test_case.rb', line 178

attr_reader :connection, :subscription

#subscription (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/channel/test_case.rb', line 178

attr_reader :connection, :subscription