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 test double representing string_or_model_class with common ActiveModel methods stubbed out. Additional methods may be easily stubbed (via add_stubs) if stubs is passed. This is most useful for impersonating models that don't exist yet.

NOTE that only ActiveModel's methods, plus new_record?, are stubbed out implicitly. new_record? returns the inverse of persisted?, and is present only for compatibility with extension frameworks that have yet to update themselves to the ActiveModel API (which declares persisted?, not new_record?).

string_or_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


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
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
 
# File 'lib/rspec/rails/mocks.rb', line 67

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
        def self.primary_key; :id; end
      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],
                              :destroyed? => false,
                              :marked_for_destruction? => false,
                              :valid? => true,
                              :blank? => false)

  double("#{model_class.name}_#{stubs[:id]}", stubs).tap do |m|
    m.singleton_class.class_eval do
      include ActiveModelInstanceMethods
      include ActiveRecordInstanceMethods if defined?(ActiveRecord)
      include ActiveModel::Conversion
      include ActiveModel::Validations
    end
    if defined?(ActiveRecord)
      [:save, :update_attributes, :update].each do |key|
        if stubs[key] == false
          RSpec::Mocks.allow_message(m.errors, :empty?).and_return(false)
        end
      end
    end
    m.__send__(:__mock_proxy).instance_eval(<<-CODE, __FILE__, __LINE__)
      def @object.is_a?(other)
        #{model_class}.ancestors.include?(other)
      end unless #{stubs.has_key?(:is_a?)}

      def @object.kind_of?(other)
        #{model_class}.ancestors.include?(other)
      end unless #{stubs.has_key?(:kind_of?)}

      def @object.instance_of?(other)
        other == #{model_class}
      end unless #{stubs.has_key?(:instance_of?)}

      def @object.__model_class_has_column?(method_name)
        #{model_class}.respond_to?(:column_names) && #{model_class}.column_names.include?(method_name.to_s)
      end

      def @object.respond_to?(method_name, include_private=false)
        __model_class_has_column?(method_name) ? true : super
      end unless #{stubs.has_key?(:respond_to?)}

      def @object.method_missing(m, *a, &b)
        respond_to?(m) ? null_object? ? self : nil : super
      end

      def @object.class
        #{model_class}
      end unless #{stubs.has_key?(:class)}

      def @object.to_s
        "#{model_class.name}_#{to_param}"
      end unless #{stubs.has_key?(:to_s)}
    CODE
    yield m if block_given?
  end
end

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

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 stubs, if the model has a matching attribute (determined by respond_to?) it is 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.

persisted? is overridden to return the result of !id.nil? This means that by default persisted? will return true. 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 persisted? will return false, 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.

Examples:


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


210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
 
# File 'lib/rspec/rails/mocks.rb', line 210

def stub_model(model_class, stubs={})
  model_class.new.tap do |m|
    m.extend ActiveModelStubExtensions
    if defined?(ActiveRecord) && 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 = stubs.reverse_merge(:blank? => false)

    stubs.each do |message, return_value|
      if m.respond_to?("#{message}=")
        m.__send__("#{message}=", return_value)
      else
        RSpec::Mocks.allow_message(m, message).and_return(return_value)
      end
    end

    yield m if block_given?
  end
end