Module: RSpec::Rails::Mocks

Defined in:
lib/rspec/rails/mocks.rb

Defined Under Namespace

Modules: ActiveModelInstanceMethods, ActiveModelStubExtensions, ActiveRecordInstanceMethods, ActiveRecordStubExtensions

Instance Method Summary collapse

Instance Method Details

#mock_model(string_or_model_class, stubs = {}) ⇒ Object

Creates a mock object instance for a string_or_model_class with common methods stubbed out. Additional methods may be easily stubbed (via add_stubs) if stubs is passed.

model_class can be any of:

* A String representing a Class that does not exist
* A String representing a Class that extends ActiveModel::Naming
* A Class that extends ActiveModel::Naming



40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
 
# File 'lib/rspec/rails/mocks.rb', line 40

def mock_model(string_or_model_class, stubs = {})
  if String === string_or_model_class
    if Object.const_defined?(string_or_model_class)
      model_class = Object.const_get(string_or_model_class)
    else
      model_class = Object.const_set(string_or_model_class, Class.new do
        extend ActiveModel::Naming
      end)
    end
  else
    model_class = string_or_model_class
  end

  unless model_class.kind_of? ActiveModel::Naming
    raise ArgumentError.new <<-EOM
The mock_model method can only accept as its first argument:
  * A String representing a Class that does not exist
  * A String representing a Class that extends ActiveModel::Naming
  * A Class that extends ActiveModel::Naming

It received #{model_class.inspect}
EOM
  end

  stubs = stubs.reverse_merge(:id => next_id)
  stubs = stubs.reverse_merge(:persisted? => !!stubs[:id])
  stubs = stubs.reverse_merge(:destroyed? => false)
  stubs = stubs.reverse_merge(:marked_for_destruction? => false)

  mock("#{model_class.name}_#{stubs[:id]}", stubs).tap do |m|
    m.extend ActiveModelInstanceMethods
    m.singleton_class.__send__ :include, ActiveModel::Conversion
    m.singleton_class.__send__ :include, ActiveModel::Validations
    if RSpec::Rails::using_active_record?
      m.extend ActiveRecordInstanceMethods
      [:save, :update_attributes].each do |key|
        if stubs[key] == false
          m.errors.stub(:empty?) { false }
        end
      end
    end
    m.__send__(:__mock_proxy).instance_eval(<<-CODE, __FILE__, __LINE__)
      def @object.is_a?(other)
        #{model_class}.ancestors.include?(other)
      end
      def @object.kind_of?(other)
        #{model_class}.ancestors.include?(other)
      end
      def @object.instance_of?(other)
        other == #{model_class}
      end
      def @object.respond_to?(method_name)
        #{model_class}.respond_to?(:column_names) && #{model_class}.column_names.include?(method_name.to_s) || super
      end
      def @object.class
        #{model_class}
      end
      def @object.to_s
        "#{model_class.name}_#{to_param}"
      end
    CODE
    yield m if block_given?
  end
end

#stub_model(model_class, stubs = {}) ⇒ Object

:call-seq:

stub_model(Model)
stub_model(Model).as_new_record
stub_model(Model, hash_of_stubs)
stub_model(Model, instance_variable_name, hash_of_stubs)

Creates an instance of Model with to_param stubbed using a generated value that is unique to each object.. If Model is an ActiveRecord model, it is prohibited from accessing the database*.

For each key in hash_of_stubs, if the model has a matching attribute (determined by asking it) are simply assigned the submitted values. If the model does not have a matching attribute, the key/value pair is assigned as a stub return value using RSpec’s mocking/stubbing framework.

new_record? is overridden to return the result of id.nil? This means that by default new_record? will return false. If you want the object to behave as a new record, sending it as_new_record will set the id to nil. You can also explicitly set :id => nil, in which case new_record? will return true, but using as_new_record makes the example a bit more descriptive.

While you can use stub_model in any example (model, view, controller, helper), it is especially useful in view examples, which are inherently more state-based than interaction-based.

Database Independence

stub_model does not make your examples entirely database-independent. It does not stop the model class itself from loading up its columns from the database. It just prevents data access from the object itself. To completely decouple from the database, take a look at libraries like unit_record or NullDB.

Examples

stub_model(Person)
stub_model(Person).as_new_record
stub_model(Person, :to_param => 37)
stub_model(Person) do |person|
  person.first_name = "David"
end



175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
 
# File 'lib/rspec/rails/mocks.rb', line 175

def stub_model(model_class, stubs={})
  model_class.new.tap do |m|
    m.extend ActiveModelStubExtensions
    if RSpec::Rails::using_active_record? && model_class < ActiveRecord::Base
      m.extend ActiveRecordStubExtensions
      primary_key = model_class.primary_key.to_sym
      stubs = stubs.reverse_merge(primary_key => next_id)
      stubs = stubs.reverse_merge(:persisted? => !!stubs[primary_key])
    else
      stubs = stubs.reverse_merge(:id => next_id)
      stubs = stubs.reverse_merge(:persisted? => !!stubs[:id])
    end
    stubs.each do |k,v|
      m.__send__("#{k}=", stubs.delete(k)) if m.respond_to?("#{k}=")
    end
    m.stub(stubs)
    yield m if block_given?
  end
end