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diff --git a/lecture_notes/test_driven_development/lab_workbook.rst b/lecture_notes/test_driven_development/lab_workbook.rst new file mode 100644 index 0000000..fa5afa4 --- /dev/null +++ b/lecture_notes/test_driven_development/lab_workbook.rst @@ -0,0 +1,146 @@ +====================================== +Lab Workbook - Test Driven Development +====================================== + +The notation that follows every question denotes the level on the +Revised Bloom's Taxonomy. + +Lab - 1 +======= + + 1. Write a stub function for calculating the LCM of two numbers. + - U-level + 2. Write the tests for the LCM function, place the tests in if + __name__ == '__main__': part of the Python file. Demonstrate that + the tests fail. - U-level + 3. Implement the code for the LCM function, using the gcd function + provided in the examples in the chapter. Demonstrate the tests + pass. (For the algorithm refer to Wikipedia - [0]) - Ap-level + 4. Alternatively, build a set of test cases, preferably a large + number of cases, place it in a text file and use these test cases + to test your LCM function. Demonstrate that tests still continue + to pass. - U-level + +[0] - http://en.wikipedia.org/wiki/Least_common_multiple#Reduction_by_the_greatest_common_divisor + +Lab - 2 +======= + + 1. Write the stub function, followed by the tests(demonstrating the + failed tests), in turn followed by the code(demonstrating the + passing tests) to calculate the number of days between two + dates. Name your function num_of_days(). The function should take + two arguments, both being tuples. Each tuple represents the date + in the format of (dd, mm, yyyy) where dd, mm and yyyy are + integers. - Ap-level + + 2. Rewrite the num_of_days() function to take the start date as an + optional argument. If the start date is not specified calculate + the number of days between the only specified date since Unix + epoch. Prior to manipulating the code to do this, make sure you + change the tests, make them fail and then refactor the code. + - Ap-level + + +Lab -3 +====== + + 1. Move the tests that were written to GCD function in the examples + of this chapter to a separate function called test_gcd(). Do the + same for LCM function and num_of_days() function. Make sure when + the respective Python files are executed as stand alone scripts + these tests executed. - U-level + 2. Put all these files in a single directory called utils and run + the nosetests command. Make a report of the results. - U-level + 3. Write doctests to each of the above functions. Demonstrate and + report the results as executed by running the doctests using + doctest.testmod() function and using nosetests command. -Ap-level + +Lab - 4 +======= + + 1. Consider the following use case: We are given a large list of + items called *data* where each item is a again a list with three + values: username, which is a string; status of the user which + can be one of the following three strings 'new', 'valid' or + 'invalid'; and the last login time which is a datetime Python + object. Write a function called **query** that takes a filter + dictionary as a parameter and returns the result of the items in + the *data* list. They keys of the dictionary can be 'user', + 'status' and 'logtime' and their corresponding values can be any + of the valid values for the corresponding key. Example filter + dictionary:: + + filter = { + 'user': 'john' + 'status': 'new' + } + + Place your function in a file called query.py. Before writing the + actual function, follow the test driven development + approach. First write a stub, fail the tests and then write the + code and make sure the tests pass. Specifically use unittest + framework to test this function. Place your tests in a file + called test_query.py + + A developer wrote a small utility function in a file named + user_utils.py which uses your **query** function which looks as + follows:: + + def login_util(user=None): + """Takes a user name and returns his last login time if the + user is a valid user, else return None. If the user is + 'host' it returns the last login time of all the users. + """ + + filter_dict = { + 'user': user + 'status': 'active' + } + + if user == 'host': + filter_dict['status'] + ['new', 'invalid'] + + return query(filter_dict) + + Unfortunately the developer did not provide us with the test + cases. We wrote the following test cases for you to only discover + that the function miserably fails. + + The tests were placed in a file called test_user_utils.py and we + have used the unittest framework:: + + import query + import user_utils + import unittest + + class TestUserUtils(unittest.TestCase): + + def setUp(self): + """Boiler plate method to provide common data to all + the test methods. + """ + self.test_names = ['Alex', 'Guido', 'Thomas', 'host', + 'Tom', 'James'] + self.data_len = len(query.data) + + def test_login_utils(self): + """Tests for the login_utils function. + """ + + for name in self.test_names: + if name == 'host': + assertEqual(len(user_utils.login_utils(name)), self.data_len) + else: + assertLess(len(user_utils.login_utils(name)), self.data_len) + + def tearDown(self): + """Boiler plate method to clean up all the data created + for tests. + """ + + del self.test_names + del self.data_len + + Fix the bug, run the tests to make sure the function passes the + tests and if possible refactor the code with a better approach. - An-level |