class FlexMock::PartialMockProxy

PartialMockProxy is used to mate the mock framework to an existing object. The object is “enhanced” with a reference to a mock object (stored in @flexmock_proxy). When the should_receive method is sent to the proxy, it overrides the existing object's method by creating singleton method that forwards to the mock. When testing is complete, PartialMockProxy will erase the mocking infrastructure from the object being mocked (e.g. remove instance variables and mock singleton methods).

Constants

MOCK_METHODS

The following methods are added to partial mocks so that they can act like a mock.

Attributes

mock[R]

Public Class Methods

make_proxy_for(obj, container, name, safe_mode) click to toggle source

Make a partial mock proxy and install it on the target obj.

# File lib/flexmock/partial_mock.rb, line 32
def self.make_proxy_for(obj, container, name, safe_mode)
  name ||= "flexmock(#{obj.class.to_s})"
  if ! proxy_defined_on?(obj)
    mock = FlexMock.new(name, container)
    proxy = PartialMockProxy.new(obj, mock, safe_mode)
    obj.instance_variable_set("@flexmock_proxy", proxy)
  end
  obj.instance_variable_get("@flexmock_proxy")
end
new(obj, mock, safe_mode) click to toggle source

Initialize a PartialMockProxy object.

# File lib/flexmock/partial_mock.rb, line 59
def initialize(obj, mock, safe_mode)
  @obj = obj
  @mock = mock
  @method_definitions = {}
  @methods_proxied = []
  unless safe_mode
    add_mock_method(:should_receive)
    MOCK_METHODS.each do |sym|
      unless @obj.respond_to?(sym)
        add_mock_method(sym)
      end
    end
  end
end
proxy_defined_on?(obj) click to toggle source

Is there a mock proxy defined on the domain object?

# File lib/flexmock/partial_mock.rb, line 43
def self.proxy_defined_on?(obj)
  obj.instance_variable_defined?("@flexmock_proxy") &&
    obj.instance_variable_get("@flexmock_proxy")
end

Public Instance Methods

add_mock_method(method_name) click to toggle source
# File lib/flexmock/partial_mock.rb, line 119
def add_mock_method(method_name)
  stow_existing_definition(method_name)
  target_class_eval do
    define_method(method_name) { |*args, &block|
      proxy = instance_variable_get("@flexmock_proxy") or
        fail "Missing FlexMock proxy " +
             "(for method_name=#{method_name.inspect}, self=\#{self})"
      proxy.send(method_name, *args, &block)
    }
  end
end
any_instance(&block) click to toggle source

#any_instance is present for backwards compatibility with version 0.5.0. @deprecated

# File lib/flexmock/deprecated_methods.rb, line 54
def any_instance(&block)
  $stderr.puts "any_instance is deprecated, use new_instances instead."
  new_instances(&block)
end
flexmock_based_on(*args) click to toggle source

Forward the based on request.

# File lib/flexmock/partial_mock.rb, line 232
def flexmock_based_on(*args)
  @mock.flexmock_based_on(*args)
end
flexmock_calls() click to toggle source

Forward to the mock

# File lib/flexmock/partial_mock.rb, line 217
def flexmock_calls
  @mock.flexmock_calls
end
flexmock_container() click to toggle source

Forward to the mock's container.

# File lib/flexmock/partial_mock.rb, line 207
def flexmock_container
  @mock.flexmock_container
end
flexmock_container=(container) click to toggle source

Set the proxy's mock container. This set value is ignored because the proxy always uses the container of its mock.

# File lib/flexmock/partial_mock.rb, line 223
def flexmock_container=(container)
end
flexmock_define_expectation(location, *args) click to toggle source
# File lib/flexmock/partial_mock.rb, line 104
def flexmock_define_expectation(location, *args)
  EXP_BUILDER.parse_should_args(self, args) do |method_name|
    unless @methods_proxied.include?(method_name)
      hide_existing_method(method_name)
    end
    ex = @mock.flexmock_define_expectation(location, method_name)
    ex.mock = self
    ex
  end
end
flexmock_expectations_for(method_name) click to toggle source

Forward the request for the expectation director to the mock.

# File lib/flexmock/partial_mock.rb, line 227
def flexmock_expectations_for(method_name)
  @mock.flexmock_expectations_for(method_name)
end
flexmock_find_expectation(*args) click to toggle source
# File lib/flexmock/partial_mock.rb, line 115
def flexmock_find_expectation(*args)
  @mock.flexmock_find_expectation(*args)
end
flexmock_get() click to toggle source

Get the mock object for the partial mock.

# File lib/flexmock/partial_mock.rb, line 75
def flexmock_get
  @mock
end
flexmock_invoke_original(method, args) click to toggle source

Invoke the original definition of method on the object supported by the stub.

# File lib/flexmock/partial_mock.rb, line 183
def flexmock_invoke_original(method, args)
  method_proc = @method_definitions[method]
  method_proc.call(*args)
end
flexmock_received?(*args) click to toggle source

Forward to the mock

# File lib/flexmock/partial_mock.rb, line 212
def flexmock_received?(*args)
  @mock.flexmock_received?(*args)
end
flexmock_teardown() click to toggle source

Remove all traces of the mocking framework from the existing object.

# File lib/flexmock/partial_mock.rb, line 195
def flexmock_teardown
  if ! detached?
    @methods_proxied.each do |method_name|
      remove_current_method(method_name)
      restore_original_definition(method_name)
    end
    @obj.instance_variable_set("@flexmock_proxy", nil)
    @obj = nil
  end
end
flexmock_verify() click to toggle source

Verify that the mock has been properly called. After verification, detach the mocking infrastructure from the existing object.

# File lib/flexmock/partial_mock.rb, line 190
def flexmock_verify
  @mock.flexmock_verify
end
should_receive(...) click to toggle source
new_instances { |instance| instance.should_receive(...) }

#new_instances is a short cut method for overriding the behavior of any new instances created via a mocked class object.

By default, #new_instances will mock the behaviour of the :new method. If you wish to mock a different set of class methods, just pass a list of symbols to as arguments. (previous versions also mocked :allocate by default. If you need :allocate to be mocked, just request it explicitly).

For example, to stub only objects created by :make (and not :new), use:

flexmock(ClassName).new_instances(:make).should_receive(...)
# File lib/flexmock/partial_mock.rb, line 149
def new_instances(*allocators, &block)
  fail ArgumentError, "new_instances requires a Class to stub" unless
    Class === @obj
  location = caller.first
  allocators = [:new] if allocators.empty?
  expectation_recorder = ExpectationRecorder.new
  allocators.each do |allocate_method|
    check_allocate_method(allocate_method)
    flexmock_define_expectation(location, allocate_method).and_return { |*args|
      create_new_mocked_object(
        allocate_method, args, expectation_recorder, block)
    }
  end
  expectation_recorder
end
should_receive(:method_name) click to toggle source
should_receive(:method1, method2, ...)
should_receive(:meth1 => result1, :meth2 → result2, ...)

Declare that the partial mock should receive a message with the given name.

If more than one method name is given, then the mock object should expect to receive all the listed melthods. If a hash of method name/value pairs is given, then the each method will return the associated result. Any expectations applied to the result of should_receive will be applied to all the methods defined in the argument list.

An expectation object for the method name is returned as the result of this method. Further expectation constraints can be added by chaining to the result.

See Expectation for a list of declarators that can be used.

# File lib/flexmock/partial_mock.rb, line 99
def should_receive(*args)
  location = caller.first
  flexmock_define_expectation(location, *args)
end

Private Instance Methods

check_allocate_method(allocate_method) click to toggle source
# File lib/flexmock/partial_mock.rb, line 238
def check_allocate_method(allocate_method)
  if allocate_method == :allocate && RUBY_VERSION >= "1.9"
    fail UsageError,
      "Cannot mock the allocation method using new_instances in Ruby 1.9"
  end
end
create_alias_for_existing_method(method_name) click to toggle source

Create an alias for the existing method_name. Returns the new alias name. If the aliasing process fails (because the method doesn't really exist, then return nil.

# File lib/flexmock/partial_mock.rb, line 299
def create_alias_for_existing_method(method_name)
  new_alias = new_name(method_name)
  unless @obj.respond_to?(new_alias)
    safe_alias_method(new_alias, method_name)
  end
  new_alias
end
create_aliased_definition(my_object, new_alias) click to toggle source

Create a method definition that invokes the original behavior via the alias.

# File lib/flexmock/partial_mock.rb, line 284
def create_aliased_definition(my_object, new_alias)
  Proc.new { |*args|
    block = nil
    if Proc === args.last
      block = args.last
      args = args[0...-1]
    end
    my_object.send(new_alias, *args, &block)
  }
end
create_new_mocked_object(allocate_method, args, recorder, block) click to toggle source

Create a new mocked object.

The mocked object is created using the following steps: (1) Allocate with the original allocation method (and args) (2) Pass to the block for custom configuration. (3) Apply any recorded expecations

# File lib/flexmock/partial_mock.rb, line 172
def create_new_mocked_object(allocate_method, args, recorder, block)
  new_obj = flexmock_invoke_original(allocate_method, args)
  mock = flexmock_container.flexmock(new_obj)
  block.call(mock) unless block.nil?
  recorder.apply(mock)
  new_obj
end
define_proxy_method(method_name) click to toggle source

Define a proxy method that forwards to our mock object. The proxy method is defined as a singleton method on the object being mocked.

# File lib/flexmock/partial_mock.rb, line 324
def define_proxy_method(method_name)
  if method_name.to_s =~ /=$/
    eval_line = __LINE__ + 1
    target_class_eval %Q{
      def #{method_name}(*args, &block)
        instance_variable_get('@flexmock_proxy').
          mock.__send__(:#{method_name}, *args, &block)
      end
    }, __FILE__, eval_line
  else
    eval_line = __LINE__ + 1
    target_class_eval %Q{
      def #{method_name}(*args, &block)
        instance_variable_get('@flexmock_proxy').
          mock.#{method_name}(*args, &block)
      end
    }, __FILE__, eval_line
    _ = true       # make rcov recognize the above eval is covered
  end
end
detached?() click to toggle source

Have we been detached from the existing object?

# File lib/flexmock/partial_mock.rb, line 369
def detached?
  @obj.nil?
end
hide_existing_method(method_name) click to toggle source

Hide the existing method definition with a singleton defintion that proxies to our mock object. If the current definition is a singleton, we need to record the definition and remove it before creating our own singleton method. If the current definition is not a singleton, all we need to do is override it with our own singleton.

# File lib/flexmock/partial_mock.rb, line 266
def hide_existing_method(method_name)
  stow_existing_definition(method_name)
  define_proxy_method(method_name)
end
new_name(old_name) click to toggle source

Generate a name to be used to alias the original behavior.

# File lib/flexmock/partial_mock.rb, line 374
def new_name(old_name)
  "flexmock_original_behavior_for_#{old_name}"
end
remove_current_method(method_name) click to toggle source

Remove the current method if it is a singleton method of the object being mocked.

# File lib/flexmock/partial_mock.rb, line 364
def remove_current_method(method_name)
  target_class_eval { remove_method(method_name) }
end
restore_original_definition(method_name) click to toggle source

Restore the original singleton defintion for method_name that was saved earlier.

# File lib/flexmock/partial_mock.rb, line 347
def restore_original_definition(method_name)
  begin
    method_def = @method_definitions[method_name]
    if method_def
      the_alias = new_name(method_name)
      target_class_eval do
        alias_method(method_name, the_alias)
      end
    end
  rescue NameError => _
    # Alias attempt failed
    nil
  end
end
safe_alias_method(new_alias, method_name) click to toggle source

Create an alias for the existing method named method_name. It is possible that method_name is implemented via a meta-programming, so we provide for the case that the method_name does not exist.

# File lib/flexmock/partial_mock.rb, line 311
def safe_alias_method(new_alias, method_name)
  target_class_eval do
    begin
      alias_method(new_alias, method_name)
    rescue NameError
      nil
    end
  end
end
singleton?(method_name) click to toggle source
# File lib/flexmock/partial_mock.rb, line 256
def singleton?(method_name)
  @obj.flexmock_singleton_defined?(method_name)
end
stow_existing_definition(method_name) click to toggle source

Stow the existing method definition so that it can be recovered later.

# File lib/flexmock/partial_mock.rb, line 273
def stow_existing_definition(method_name)
  @methods_proxied << method_name
  new_alias = create_alias_for_existing_method(method_name)
  if new_alias
    @method_definitions[method_name] = create_aliased_definition(@obj, new_alias)
  end
  remove_current_method(method_name) if singleton?(method_name)
end
target_class_eval(*args, &block) click to toggle source

Evaluate a block (or string) in the context of the singleton class of the target partial object.

# File lib/flexmock/partial_mock.rb, line 252
def target_class_eval(*args, &block)
  target_singleton_class.class_eval(*args, &block)
end
target_singleton_class() click to toggle source

The singleton class of the object.

# File lib/flexmock/partial_mock.rb, line 246
def target_singleton_class
  class << @obj; self; end
end