rspec refactoring? - ruby-on-rails

Question

I have the following test, with two almost identical blocks. Now i am looking for ways to refactor this cleanly.
The test:
context "with the d1 configuration" do
before (:each) do
# send a message
#envelope = Factory(:envelope, :destination => '32495xxxxxx', :message => 'Message sent by d1')
#distributor = Distributor.find_by_name(Distributor::D1)
#result = #envelope.send_to(#distributor)
end
it "should created a new sms-message" do
#envelope.sent_messages.size.should == 1
end
it "should have created one sms-message linked to the envelope and distributor" do
sms = #envelope.sent_messages.find_by_distributor_id(#distributor.id)
sms.should be_instance_of(SentMessage)
sms.external_message_id.should_not == nil
sms.sent_message_status_id.should == SentMessageStatus::IN_PROGRESS
end
it "should add a logline for the creation of the sms-message" do
#envelope.log_lines.size.should == 2
#envelope.log_lines.last.message.should =~ /^Sent message/
end
end
context "with the correct d2 configuration" do
before (:each) do
# send a message
#envelope = Factory(:envelope, :destination => '32495xxxxxx', :message => 'Message sent by d2')
#distributor = Distributor.find_by_name(Distributor::D2)
#result = #envelope.send_to(#distributor)
end
it "should created a new sms-message" do
#envelope.sent_messages.size.should == 1
end
it "should have created one sms-message linked to the envelope and distributor" do
sms = #envelope.sent_messages.find_by_distributor_id(#distributor.id)
sms.should be_instance_of(SentMessage)
sms.external_message_id.should_not == nil
sms.sent_message_status_id.should == SentMessageStatus::IN_PROGRESS
end
it "should add a logline for the creation of the sms-message" do
#envelope.log_lines.size.should == 2
#envelope.log_lines.last.message.should =~ /^Sent message/
end
end
As you can tell, two identical code blocks, each for a different distributor, D1 and D2 (in our project they have more meaningful names :)) -- and now i need to add a third distributor. How do i go about this?
I can loop over an array containing the changing parts (in this case: distributor-name and the message contents). But can i also change the test-name?
What are the best approaches here? Is it possible to make some kind of test-template, where you can fill in certain values and execute that?

Answer 1

I had a pair-programming session with a more experienced collegue of mine, and together we came up with the following solution.
We defined some shared behaviour first:
subject {#envelope}
let(:the_sent_message){ #envelope.sent_messages.find_by_distributor_id(#distributor.id)}
shared_examples_for "a typical sent envelope" do
it{should have(1).sent_messages }
it{should have(2).log_lines }
end
shared_examples_for "a successful delivery" do
it("should have 1 IN_PROGRESS sms-message") { the_sent_message.should be_in_progress }
it "should have 1 sms-message with external ref" do
the_sent_message.external_message_id.should_not == nil
end
it "should log the delivery success" do
#envelope.log_lines.last.message.should =~ /^Sent message/
end
end
shared_examples_for "a failing delivery" do
it("should have 1 FAILED sms-message") { the_sent_message.should be_failed }
it "should have 1 sms-message and no external ref" do
the_sent_message.external_message_id.should == nil
end
it "should log the delivery failure" do
#envelope.log_lines.last.message.should =~ /^Failed to send/
end
end
and then the tests become way more readable!
context "delivered by d1" do
before do
#distributor = Distributor.find_by_name(Distributor::D1)
send_a_test_envelope_to(#distributor)
end
it_should_behave_like "a typical sent envelope"
it_should_behave_like "a successful delivery"
end
context "delivered by d2" do
before do
#distributor = Distributor.find_by_name(Distributor::D2)
send_a_test_envelope_to(#distributor)
end
it_should_behave_like "a typical sent envelope"
it_should_behave_like "a successful delivery"
end
and we also extracted the following method
def send_a_test_envelope_to(distributor)
#envelope = Factory(:envelope, :destination => '32495xxxxxx', :message => "Message sent by #{#distributor.name}")
#envelope.send_to(distributor)
end
Now i could still apply the suggested answer #Taryn proposed, but i am not entirely sure it is really needed anymore.

Answer 2

Yes, you can loop through an array/hash full of examples and yes you can rename contexts based on that but you'll have to be aware of scoping issues - eg a context is a class-level scope, but a test is an instance.
Thus you have to setup these things in instance-variables in the "setup" section of a context.
I've mainly done this stuff with unit:test+shoulda (rather than rspec) so I may have messed up the scoping rules somewhat, but they should be similarish
Note: I haven't tested the code below, so it may be prey to such issues...
# name this better than I have
CONFIGS = {'d1' => {:name => Distributor::D1
:destination => '32495xxxxxx',
:message => 'd1 message'},
'd2' => {:name => Distributor::D2
:destination => '98765xxxxxx',
:message => 'd2 message'}
} # etc
CONFIGS.each do |display_name, dist_hash|
context "with the #{display_name} configuration" do
before (:each) do
# scope the value-hash here to make it available to test-cases
# (you don't have to if you're just using it in the setup section)
#dist_hash = dist_hash
# send a message
#envelope = Factory(:envelope, :destination => #dist_hash[:destination], :message => #dist_hash[:message])
#distributor = Distributor.find_by_name(#dist_hash[:name])
#result = #envelope.send_to(#distributor)
end
it "should created a new sms-message" do
#envelope.sent_messages.size.should == 1
end
it "should have created one sms-message linked to the envelope and distributor" do
sms = #envelope.sent_messages.find_by_distributor_id(#distributor.id)
sms.should be_instance_of(SentMessage)
sms.external_message_id.should_not == nil
sms.sent_message_status_id.should == SentMessageStatus::IN_PROGRESS
end
it "should add a logline for the creation of the sms-message" do
#envelope.log_lines.size.should == 2
#envelope.log_lines.last.message.should =~ /^Sent message/
end
end
end