mocks and stubs example in rspec

mocks_and_stubs.rb

#Mocks and stubs way

#The other option is to use mocks and stubs. Although there is a lot of information in the web about it, to help our discussion, I will #describe it very shortly. From my experience & research, I understand that the main difference between those two is the following:

#Stubbing a method is all about replacing the method with code that returns a specified result (or perhaps raises a specified exception). #Mocking a method is all about asserting that a method has been called (perhaps with particular parameters).

#As you can see, stubbing lets you define methods that are not currently implemented or we decided not to depend on. On the other hand, as we #mock objects we specify the behavior that we would expect on the mocked object, making our test more Behavior Driven Development.

#This is the recommended way of using Rspec as it defines the way the objects must collaborate to accomplish a certain task.

#Here we show how we implement the chat's example using mocks.

#spec/views/chat/show.html.erb_spec.rb
describe "/chats/show.html.erb" do
include ChatsHelper

before(:each) do
@chat = mock_model(Chat)
@chat.stub!(:name).and_return("MyString")
@chat.stub!(:id).and_return(1)
@chat.stub!(:to_param).and_return(1)
message_1 = mock_model(Message)
message_1.stub!(:data).and_return("Hello!")
message_1.stub!(:version).and_return(1)
message_2 = mock_model(Message)
message_2.stub!(:data).and_return("How are you?")
message_2.stub!(:version).and_return(2)
message_3 = mock_model(Message)
message_3.stub!(:data).and_return("Excellent!")
message_3.stub!(:version).and_return(3)
@messages = [message_1, message_2, message_3]
@chat.stub!(:messages).and_return(@messages)
@message.stub!(:data)
assigns[:chat] = @chat
render "/chats/show.html.erb"
end

it "should render attributes in paragraph" do
response.should have_text(/MyString/)
end

it "should render all messages for the chat" do
response.should have_tag("tr>td", "Hello!", 1)
response.should have_tag("tr>td", "How are you?", 1)
response.should have_tag("tr>td", "Excellent!", 1)
end

end

#As you can see, the idea behind mocks is to define some behavior that should be part of certain task, and it is very human readable as it #uses many features of Rspec mocks.