Test-driven development¶

We will do this exercise in pairs. Not only we will learn how to do test-driven development, but we will also exercise collaborative GitHub workflow, and get to know two great services for automated testing (Travis) and code coverage analysis (Coveralls).

First find a partner who speaks the same programming language as you. Then proceed as follows:

Create a GitHub project for this exercise (both of you create one).

Sign in to https://travis-ci.org and https://coveralls.io with your GitHub account and enable there your new GitHub project.

Create two or three unit tests for functions which do not exist yet.

Do not implement the functions, only their tests and stubs of the functions.

Example (Python; the function get_word_lengths currently fails):

def get_word_lengths(s):
    """
    Returns a list of integers representing
    the word lengths in string s.
    """
    return None


def test_get_word_lengths():
    text = "Three tomatoes are walking down the street"
    assert get_word_lengths(text) == [5, 8, 3, 7, 4, 3, 6]

Then:

Check that the test fails (since the function is not implemented/finished).
Commit the function and its test.
Create a .travis.yml file based on provided examples (below) and commit it.
Push the tests and function stubs to GitHub and verify that the tests fail on Travis.

Now your programming partner forks your repository and you fork hers/his. Then:

Fix the function/routine until the test(s) pass(es).
Commit and push the working function/routine.
Check and discuss the test history on https://travis-ci.org.
Check and discuss the test coverage on https://coveralls.io.
Iterate and refine.

When you are finished, submit your work as pull request and your programming partner will review and possibly accept the changes.

Examples that you can use as a starting point: