Homework 1: Writing Specifications with Hypothesis

Due date: Friday, January 23 at 11:59pm

This homework is about writing specifications and testing with Hypothesis. There are three parts to this homework. Part 1 is a series of mini-exercises. Part 2 is a more extended case study, and Part 3 asks you to use Hypothesis to find a bug in a program.

Getting started

To get started, make sure you have completed Homework 0. in particular, you should have Python, Hypothesis, Pytest, and Z3 installed. Then clone the repository with git clone, and open and edit the files part1.py, part2.py, part3.py.

To run the code, you can use

pytest part1.py
pytest part2.py
pytest part3.py

We will submit the homework through Gradescope.

Grading notes

• Don't change the function signatures unless you are asked to do so. This ensures that our gradings scripts will work correctly.

• Please do not use any external libraries. All problems are solvable without external libraries.

• Please do not modify the file names or the list of test_ functions in parts 1, 2, and 3, as your results will be compared with the official rubric. If you want to add other tests, remember to comment them out after.

• If your code is correct, there should be no pytest failures (shown in red) -- instead, you should be using the annotation pytest.mark.xfail to mark tests that are expected to fail. These will show up in yellow.

• Make sure your answers to free response questions are between the ===== ANSWER HERE ===== and ===== END ANSWER ===== markers, and don't remove the markers.

• We won't be able to give credit to code that doesn't run, so please double check that your code runs before submitting. You should be able to run pytest <yourfile>.py and see a list of successful, skipped, and expected failing test cases. If you have some broken code, please remember to comment out the broken parts of each function (or use @pytest.mark.skip to skip the unit tests) to ensure you receive some partial credit.