Book Image

Test-Driven Python Development

By : Siddharta Govindaraj
Book Image

Test-Driven Python Development

By: Siddharta Govindaraj

Overview of this book

This book starts with a look at the test-driven development process, and how it is different from the traditional way of writing code. All the concepts are presented in the context of a real application that is developed in a step-by-step manner over the course of the book. While exploring the common types of smelly code, we will go back into our example project and clean up the smells that we find. Additionally, we will use mocking to implement the parts of our example project that depend on other systems. Towards the end of the book, we'll take a look at the most common patterns and anti-patterns associated with test-driven development, including integration of test results into the development process.
Table of Contents (20 chapters)
Test-Driven Python Development
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Writing tests for nose2


Apart from picking up the existing tests written with the unittest module and running them, nose2 also supports new ways of writing tests.

To start with, nose2 allows tests to be regular functions. We don't need to create a class and inherit it from any base class. As long as the function starts with the word test, it is considered a test and executed.

We can take the following test:

class StockTest(unittest.TestCase):
    def setUp(self):
        self.goog = Stock("GOOG")

    def test_price_of_a_new_stock_class_should_be_None(self):
        self.assertIsNone(self.goog.price)

And write the above test as follows:

def test_price_of_a_new_stock_class_should_be_None():
    goog = Stock("GOOG")
    assert goog.price is None

As we can see, writing tests this way reduces some of the boilerplate code that we had to do before:

  • We no longer have to create a class to hold the tests in

  • We no longer have to inherit from any base class

  • We don't even have to import the unittest module

We...