Programming a web API with test driven development

Question

I'm creating a web API in Python which communicates with some other web API's (Facebook, twitter, etc) en a other web API which is programmed at the same time as my API.

Since I like to use test driven development, I wonder how I can apply TDD to my web API. I know about mocking but how can I mock other API's and how can I mock calls to my API.

Update 1: To specify my question. Is it possible to create a web API with TDD under the conditions specified above. If yes, is there a library I can use in Python to do so?

Answer 1

Since your question is rather broad, I'll just refer you:

• for mocking in python there is a library called Mock, documentation is pretty detailed
• Python Unit Testing with Mock
• What is your favorite Python mocking library?

Here's a simple example of using mock to mock python-twitter's GetSearch method:

• test_module.py

  import twitter
  
  
  def get_tweets(hashtag):
      api = twitter.Api(consumer_key='consumer_key',
                        consumer_secret='consumer_secret',
                        access_token_key='access_token',
                        access_token_secret='access_token_secret')
      api.VerifyCredentials()
      results = api.GetSearch(hashtag)
      return results
  

• test_my_module.py

  from unittest import TestCase
  from mock import patch
  import twitter
  from my_module import get_tweets
  
  
  class MyTestCase(TestCase):
      def test_ok(self):
          with patch.object(twitter.Api, 'GetSearch') as search_method:
              search_method.return_value = [{'tweet1', 'tweet2'}]
  
              self.assertEqual(get_tweets('blabla'), [{'tweet1', 'tweet2'}])
  

You probably should mock the whole Api object in your unittests in order to still call them unit tests. Hope that helps.