module ActiveModel::Serializer::Lint::Tests

Active Model Serializer Lint Tests

You can test whether an object is compliant with the Active Model Serializers API by including ActiveModel::Serializer::Lint::Tests in your TestCase. It will include tests that tell you whether your object is fully compliant, or if not, which aspects of the API are not implemented.

Note an object is not required to implement all APIs in order to work with Active Model Serializers. This module only intends to provide guidance in case you want all features out of the box.

These tests do not attempt to determine the semantic correctness of the returned values. For instance, you could implement serializable_hash to always return +{}+, and the tests would pass. It is up to you to ensure that the values are semantically meaningful.

Public Instance Methods

test_active_model_errors() click to toggle source
# File lib/active_model/serializer/lint.rb, line 126
def test_active_model_errors
  assert_respond_to resource, :errors
end
test_active_model_errors_human_attribute_name() click to toggle source
# File lib/active_model/serializer/lint.rb, line 130
def test_active_model_errors_human_attribute_name
  assert_respond_to resource.class, :human_attribute_name
  assert_equal(-2, resource.class.method(:human_attribute_name).arity)
end
test_active_model_errors_lookup_ancestors() click to toggle source
# File lib/active_model/serializer/lint.rb, line 135
def test_active_model_errors_lookup_ancestors
  assert_respond_to resource.class, :lookup_ancestors
  assert_equal 0, resource.class.method(:lookup_ancestors).arity
end
test_as_json() click to toggle source

Passes if the object responds to as_json and if it takes zero or one arguments. Fails otherwise.

as_json returns a hash representation of a serialized object. It may delegate to serializable_hash Typically, it is implemented either by including ActiveModel::Serialization which includes ActiveModel::Serializers::JSON. or by the JSON gem when required.

# File lib/active_model/serializer/lint.rb, line 58
def test_as_json
  assert_respond_to resource, :as_json
  resource.as_json
  resource.as_json(nil)
end
test_cache_key() click to toggle source

Passes if the object responds to cache_key Fails otherwise.

cache_key returns a (self-expiring) unique key for the object, and is part of the (self-expiring) cache_key, which is used by the adapter. It is not required unless caching is enabled.

# File lib/active_model/serializer/lint.rb, line 83
def test_cache_key
  assert_respond_to resource, :cache_key
  actual_arity = resource.method(:cache_key).arity
  assert_includes [-1, 0], actual_arity, "expected #{actual_arity.inspect} to be 0 or -1"
end
test_id() click to toggle source

Passes if the object responds to id and if it takes no arguments. Fails otherwise.

id returns a unique identifier for the object. It is not required unless caching is enabled.

# File lib/active_model/serializer/lint.rb, line 108
def test_id
  assert_respond_to resource, :id
  assert_equal 0, resource.method(:id).arity
end
test_model_name() click to toggle source

Passes if the object's class responds to model_name and if it is in an instance of ActiveModel::Name. Fails otherwise.

model_name returns an ActiveModel::Name instance. It is used by the serializer to identify the object's type. It is not required unless caching is enabled.

# File lib/active_model/serializer/lint.rb, line 120
def test_model_name
  resource_class = resource.class
  assert_respond_to resource_class, :model_name
  assert_instance_of resource_class.model_name, ActiveModel::Name
end
test_read_attribute_for_serialization() click to toggle source

Passes if the object responds to read_attribute_for_serialization and if it requires one argument (the attribute to be read). Fails otherwise.

read_attribute_for_serialization gets the attribute value for serialization Typically, it is implemented by including ActiveModel::Serialization.

# File lib/active_model/serializer/lint.rb, line 40
def test_read_attribute_for_serialization
  assert_respond_to resource, :read_attribute_for_serialization, 'The resource should respond to read_attribute_for_serialization'
  actual_arity = resource.method(:read_attribute_for_serialization).arity
  # using absolute value since arity is:
  #  1 for def read_attribute_for_serialization(name); end
  # -1 for alias :read_attribute_for_serialization :send
  assert_equal 1, actual_arity.abs, "expected #{actual_arity.inspect}.abs to be 1 or -1"
end
test_serializable_hash() click to toggle source

Passes if the object responds to serializable_hash and if it takes zero or one arguments. Fails otherwise.

serializable_hash returns a hash representation of a object's attributes. Typically, it is implemented by including ActiveModel::Serialization.

# File lib/active_model/serializer/lint.rb, line 28
def test_serializable_hash
  assert_respond_to resource, :serializable_hash, 'The resource should respond to serializable_hash'
  resource.serializable_hash
  resource.serializable_hash(nil)
end
test_to_json() click to toggle source

Passes if the object responds to to_json and if it takes zero or one arguments. Fails otherwise.

to_json returns a string representation (JSON) of a serialized object. It may be called on the result of as_json. Typically, it is implemented on all objects when the JSON gem is required.

# File lib/active_model/serializer/lint.rb, line 71
def test_to_json
  assert_respond_to resource, :to_json
  resource.to_json
  resource.to_json(nil)
end
test_updated_at() click to toggle source

Passes if the object responds to updated_at and if it takes no arguments. Fails otherwise.

updated_at returns a Time object or iso8601 string and is part of the (self-expiring) cache_key, which is used by the adapter. It is not required unless caching is enabled.

# File lib/active_model/serializer/lint.rb, line 96
def test_updated_at
  assert_respond_to resource, :updated_at
  actual_arity = resource.method(:updated_at).arity
  assert_equal 0, actual_arity
end

Private Instance Methods

assert_instance_of(result, name) click to toggle source
# File lib/active_model/serializer/lint.rb, line 146
def assert_instance_of(result, name)
  assert result.instance_of?(name), "#{result} should be an instance of #{name}"
end
resource() click to toggle source
# File lib/active_model/serializer/lint.rb, line 142
def resource
  @resource or fail "'@resource' must be set as the linted object"
end