My presentation about Test Driven Development of HTTP clients using WebMock, presented at RubyManor 2. WebMock is a library for stubbing and setting expectations on HTTP requests in Ruby.

1. TDD of HTTP Clients
with WebMock
Bartosz Blimke
@bartoszblimke
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2. Test
TDD
RED
RED
Code
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3. Hello http://my.geoservice.org
Give me location for zip code WC1H 9EF
GET http://my.geoservice.org/?zip=WC1H 9EF
HTTP 200 - OK
Content-Type: application/json
Here is your location:
{"latitude"=>"51.52","longitude":-0.12"}
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4. describe GeoCoordinatesFinder do
it "should make http request to geocoding service" do
end
it "should report coordinates provided by geocoding service" do
end
end
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5. describe GeoCoordinatesFinder do
it "should make http request to geocoding service" do
???
end
it "should report coordinates provided by geocoding service" do
???
end
end
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8. class GeoCoordinatesFinder
def get_coordinates_by_zip_code(zip)
res = Net::HTTP.start("my.geoservice.org", 80) { |http|
http.get("/?zip=#{URI.encode(zip)}")
}
result = JSON.parse(res)
[result['latitude'], result['longitude']]
end
end
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9. describe GeoCoordinatesFinder do
before(:each) do
@coordinates_finder = GeoCoordinatesFinder.new
@mock_http = mock("http")
@res = mock(Net::HTTPOK, :body => "{"latitude":"5.5","longitude":"6.6"}")
Net::HTTP.stub!(:start).with("my.geoservice.org", 80).and_yield @mock_http
@mock_http.stub!(:get).with("/?zip=WC1H%209EF").and_return(@res)
end
it "should make http request to geocoding service" do
Net::HTTP.should_receive(:start).and_yield @mock_http
@mock_http.should_receive(:get).with("/?zip=WC1H%209EF")
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF")
end
it "should report coordinates provided by geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF").should == ["5.5", "6.6"]
end
end
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11. class GeoCoordinatesFinder
def get_coordinates_by_zip_code(zip)
url = "http://my.geoservice.org?zip=#{URI.encode(zip)}"
response = RestClient.get(url)
result = JSON.parse(response)
[result['latitude'], result['longitude']]
end
end
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13. describe GeoCoordinatesFinder do
before(:each) do
@coordinates_finder = GeoCoordinatesFinder.new
RestClient.stub!(:get).with("http://my.geoservice.org?zip=WC1H%209EF").
and_return("{"latitude":"5.5","longitude":"6.6"}")
end
it "should make http request to yahoo geocoding service" do
RestClient.should_receive(:get).with("http://my.geoservice.org?zip=WC1H%209EF")
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF")
end
it "should report coordinates provided by geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF").should == ["5.5", "6.6"]
end
end
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14. I wanted a tool for stubbing
HTTP requests that...

15. I wanted a tool for stubbing
HTTP requests that...
• doesn’t depend on usage of a specific API

16. I wanted a tool for stubbing
HTTP requests that...
• doesn’t depend on usage of a specific API
• supports stubbing based on request
method, uri, body and headers

17. I wanted a tool for stubbing
HTTP requests that...
• doesn’t depend on usage of a specific API
• supports stubbing based on request
method, uri, body and headers
• verifies expectations of requests

18. I wanted a tool for stubbing
HTTP requests that...
• doesn’t depend on usage of a specific API
• supports stubbing based on request
method, uri, body and headers
• verifies expectations of requests
• supports different HTTP libraries

19. WebMock
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20. require 'webmock/rspec'
include WebMock
describe GeoCoordinatesFinder do
before(:each) do
@coordinates_finder = GeoCoordinatesFinder.new
stub_request(:get, "http://my.geoservice.org?zip=WC1H 9EF").
to_return(:body => "{"latitude":"5.5","longitude":"6.6"}")
end
it "should make http request to geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF")
WebMock.should have_requested(:get, "http://my.geoservice.org?zip=WC1H 9EF")
end
it "should report coordinates provided by geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF").
should == ["5.5", "6.6"]
end
end
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21. require 'webmock/rspec'
include WebMock
describe GeoCoordinatesFinder do
before(:each) do
@coordinates_finder = GeoCoordinatesFinder.new
stub_request(:get, "http://my.geoservice.org?zip=WC1H 9EF").
to_return(:body => "{"latitude":"5.5","longitude":"6.6"}")
end
it "should make http request to geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF")
WebMock.should have_requested(:get, "http://my.geoservice.org?zip=WC1H 9EF")
end
it "should report coordinates provided by geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF").
should == ["5.5", "6.6"]
end
end
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22. require 'webmock/rspec'
include WebMock
describe GeoCoordinatesFinder do
before(:each) do
@coordinates_finder = GeoCoordinatesFinder.new
stub_request(:get, "http://my.geoservice.org?zip=WC1H 9EF").
to_return(:body => "{"latitude":"5.5","longitude":"6.6"}")
end
it "should make http request to geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF")
WebMock.should have_requested(:get, "http://my.geoservice.org?zip=WC1H 9EF")
end
it "should report coordinates provided by geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF").
should == ["5.5", "6.6"]
end
end
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23. require 'webmock/rspec'
include WebMock
describe GeoCoordinatesFinder do
before(:each) do
@coordinates_finder = GeoCoordinatesFinder.new
stub_request(:get, "http://my.geoservice.org?zip=WC1H 9EF").
to_return(:body => "{"latitude":"5.5","longitude":"6.6"}")
end
it "should make http request to geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF")
request(:get, "http://my.geoservice.org?zip=WC1H 9EF").should have_been_made
end
it "should report coordinates provided by geocoding service" do
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF").
should == ["5.5", "6.6"]
end
end
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25. class GeoCoordinatesFinder
def get_coordinates_by_zip_code(zip)
uri = "http://my_geoservice.org?zip=#{URI.encode(zip)}"
result = JSON.parse(HTTPClient.new.get(uri).content)
[result['latitude'], result['longitude']]
end
end
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27. Test::Unit
require 'webmock/test_unit'
include WebMock
class TestGeoCoordinatesFinder < Test::Unit::TestCase
def setup
@coordinates_finder = GeoCoordinatesFinder.new
stub_request(:get, "http://my.geoservice.org?zip=WC1H 9EF").
to_return(:body => "{"latitude":"5.5","longitude":"6.6"}")
end
def test_making_request_to_geocoding_service
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF")
assert_requested :get, "http://my.geoservice.org?zip=WC1H 9EF"
end
def test_reporting_coordinates_provided_by_geocoding_service
assert_equal @coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF"), ["5.5", "6.6"]
end
end
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28. Test::Unit
require 'webmock/test_unit'
include WebMock
class TestGeoCoordinatesFinder < Test::Unit::TestCase
def setup
@coordinates_finder = GeoCoordinatesFinder.new
stub_request(:get, "http://my.geoservice.org?zip=WC1H 9EF").
to_return(:body => "{"latitude":"5.5","longitude":"6.6"}")
end
def test_making_request_to_geocoding_service
@coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF")
assert_requested :get, "http://my.geoservice.org?zip=WC1H 9EF"
end
def test_reporting_coordinates_provided_by_geocoding_service
assert_equal @coordinates_finder.get_coordinates_by_zip_code("WC1H 9EF"), ["5.5", "6.6"]
end
end
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29. Cucumber
features/common/env.rb
require 'webmock'
include WebMock
Before do
WebMock.disable_net_connect!
WebMock.reset_webmock
end
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30. Cucumber
features/finding_geo_coordinates.feature
Feature: Finding the way to an awesome conference
In order to find the best way to Ruby Manor
As a ruby geek
I want to see how to get there on a map
Scenario: User finds zip code coordinates on a map
Given geoservice reports coordinates "51.52, -0.12" for zip code "WC1H 9EF"
When I type "WC1H 9EF" into zip code field
And I press "Show on map"
Then I should see map centered at latitude "51.52" and longitude "-0.12"
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31. Cucumber
features/step_definitions/geocoding_service_steps.rb
Given /^geoservice reports (.+), (.+) as coordinates for zip code (.+)$/ do
|lat, long, zip_code|
stub_request(:get, "http://my.geoservice.org?zip=#{zip_code}").
to_return(
:body => "{"latitude":"#{lat}","longitude":"#{long}"}"
)
end
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32. Matching Requests
on Body and Headers
stub_request(:post, "www.example.net").
with(:body => "abc", :headers => { :content_type => 'text/plain' })
RestClient.post "www.example.net", "abc", :content_type => 'text/plain'
WebMock.should have_requested(:post, "www.example.net").
with(:body => "abc", :headers => { 'Content-Type' => 'text/plain' })
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33. Smart URI Matching
www.example.net/my path?x=my params
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34. Smart URI Matching
www.example.net/my path?x=my params
www.example.net/my%20path?x=my%20params
www.example.net:80/my path?x=my params
www.example.net:80/my%20path?x=my%20params
http://www.example.net/my path?x=my params
http://www.example.net/my%20path?x=my%20params
http://www.example.net:80/my path?x=my params
http://www.example.net:80/my%20path?x=my%20params
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35. Matching URIs with Regexp
stub_request(:post, /example/).
with(:body => "abc", :headers => { :content_type => 'text/plain' })
RestClient.post "www.example.net", "abc", :content_type => 'text/plain'
WebMock.should have_requested(:post, /example/).
with(:body => "abc", :headers => { 'Content-Type' => 'text/plain' })
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36. Basic Authentication
stub_request(:any, 'user:pass@www.example.net').
to_return(:body => 'abc')
RestClient::Resource.new(
'www.example.net',
:user => 'user',
:password => 'pass'
).post('abc') # ===> "abcn"
WebMock.should have_requested(:post, 'user:pass@www.example.net')
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37. Dynamic Responses
stub_request(:any, 'www.example.net').
to_return(:body => lambda { |request| request.body })
RestClient.post('www.example.net', 'abc') # ===> "abcn"
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38. Supported Libraries
Net::HTTP HTTPClient
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39. Supported Libraries
Net::HTTP HTTPClient
HTTParty
RESTClient
RightScale::HttpConnection
open-uri
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40. http://github.com/bblimke/webmock
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41. http://github.com/bblimke/webmock
http://groups.google.com/group/webmock-users
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42. http://github.com/bblimke/webmock
http://groups.google.com/group/webmock-users
bartosz@new-bamboo.co.uk
@bartoszblimke
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43. Questions?
http://github.com/bblimke/webmock
http://groups.google.com/group/webmock-users
bartosz@new-bamboo.co.uk
@bartoszblimke
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