Intermediate unit test: Difference between revisions

Latest revision as of 20:15, 19 April 2026

Required course material for the lesson

Powerpoint: Testing
Online: pytest documentation
Resource: Unit test - start of reverse polish notation class
Blog: On testing, by the founder of StackExchange.

Subjects covered

Unit test using pytest framework.
Files, test data
Setting up real projects

Exercises to be handed in

You should make a special folder for the exercises. I will refer to my special folder as unittest in these exercises. You will also see some __pycache__ folders appear in places. This is Pythons cache for "compiled" programs. It is safe to ignore and also to delete, because it may become outdated.

Follow the file structure of having a code (or src) folder for programs, a test folder for tests, and now a testdata folder for files containing test data. Now make unit tests and appropriate test data files for your fasta class from last week. In this exercise you just need to make unit test for the method load. You need to hand in both tests and test data.
Add unit tests for the method save in your fasta class. Hand in same way as above.
Add unit tests for the method delete in your fasta class. Use a fixture for setting up a test set for you deletion tests. Hand in same way as above.
Change your unit test setup of your fasta class to the package structure. That includes the correct folder structure, pyproject.toml and __init__.py file.

I would not be surprised if you find errors in your fasta class based on these tests. I found flaws in my code.

Exercises for extra practice

Add unit tests for all methods in your fasta class. That will be a bit of work.

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 == Subjects covered ==
-Overview of test methods<br>
+Unit test using pytest framework.<br>
-Unit test using pytest framework.
+Files, test data<br>
+Setting up real projects<br>
 == Exercises to be handed in ==
 You should make a special folder for the exercises. I will refer to my special folder as ''unittest'' in these exercises. You will also see some ''__pycache__'' folders appear in places. This is Pythons cache for "compiled" programs. It is safe to ignore and also to delete, because it may become outdated.
-# Use your factorial function from exercise 2 in [[Making Functions]]. If you did not do so already, change it to use exceptions instead of '''sys.exit()''', when an error occurs. Now make simple unit tests for the following test cases: 12, 2, 1, 0, -1, 3.0, 3.4, "3", "3.1.", "ABC". The factorial function and all test functions must be in one single file (''factorial_test.py'' in ''unittest''), which you can run ''pytest'' on.<br><br>
+# Follow the file structure of having a ''code'' (or ''src'') folder for programs, a ''test'' folder for tests, and now a ''testdata'' folder for files containing test data. Now make unit tests and appropriate test data files for your '''fasta''' class from last week. In this exercise you just need to make unit test for the method '''load'''. You need to hand in both tests and test data.<br><br>
-# Now remove the factorial function from ''factorial_test.py'' and put it in its own file ''factorial.py''. Import it from the ''factorial_test.py'' like '''from factorial import factorial'''. The first factorial is the name of the .py file, the second factorial is the name of your factorial function. Just run ''pytest'' (no file name) in the folder to check it works. It is more normal to have test and function separated.<br><br>
+# Add unit tests for the method '''save''' in your '''fasta''' class. Hand in same way as above.<br><br>
-# Above we removed test code from function code by creating two files. Next, put the files in their own folder in ''unittest''. I would put my ''factorial.py'' in ''unittest/src'' and ''factorial_test.py'' in ''unittest/test''. This way there is a very clear separation between function and test. The problem is making sure the test code loads the function code. Do it wrong a couple of times - it is very instructive.<br><br>
+# Add unit tests for the method '''delete''' in your '''fasta''' class. Use a fixture for setting up a test set for you deletion tests. Hand in same way as above.<br><br>
-# Follow the file structure of having a ''code'' (or ''src'') folder for programs, a ''test'' folder for tests, and now a ''testdata'' folder for files containing test data. Now make unit tests and appropriate test data files for your '''fasta''' class from last week. In this exercise you just need to make unit test for the method '''load'''. You need to hand in both tests and test data. Maybe you should zip it all. Learn to zip :-)<br><br>
+# Change your unit test setup of your fasta class to the package structure. That includes the correct folder structure, pyproject.toml and __init__.py file.<br><br>
-# Add unit tests for the method '''save''' in your '''fasta''' class.<br><br>
-# Add unit tests for the method '''delete''' in your '''fasta''' class.<br><br>
 I would not be surprised if you find errors in your '''fasta''' class based on these tests. I found flaws in my code.
 == Exercises for extra practice ==
 # Add unit tests for all methods in your '''fasta''' class. That will be a bit of work.