Run the Tests on Every Push

Continuous integration (CI) means your tests run by themselves every time you push. On GitHub you ask for it with a workflow: a YAML file in the folder .github/workflows/, made of key: value lines nested by their indentation. The key on says which event starts it, and each job runs its steps from top to bottom on a fresh machine, the runner.

Here is a small workflow of another kind. It starts on every pull request and runs one command:

name: Hello
on: pull_request
jobs:
  greet:
    runs-on: ubuntu-latest
    steps:
      - run: echo Hello from the runner

A step either uses a ready-made action, such as actions/checkout, which copies your repository onto the runner, or runs a command, as you would type it in a terminal. The runner starts with its own Python 3.12 and nothing of yours: no code, no Flask. So the order matters: copy the code, set up the server's Python, install requirements.txt with pip install -r, then run the tests. The job stops at the first step that fails.

You write the workflow as a Python string named workflow, one line per piece, each ending in \n. The check reads it the way GitHub would, runs the job and must print:

Workflow: Tests
Starts on: push
Job test, on a fresh ubuntu-latest machine
Step 1: uses actions/checkout@v6
  copied the repository: app.py, requirements.txt, test_app.py
Step 2: uses actions/setup-python@v6 with python-version 3.13
  Python 3.13 is ready
Step 3: run pip install -r requirements.txt
  installed Flask==3.1.3 and gunicorn==23.0.0 into Python 3.13
Step 4: run python -m unittest
  Ran 3 tests: OK
The job passed: every push now runs the tests on Python 3.13.

Your task: the starting workflow already has its name and the job test on ubuntu-latest. Add the trigger on: push and four steps: check out the code with actions/checkout@v6, set up Python '3.13' with actions/setup-python@v6, install the packages from requirements.txt, and run the tests with python -m unittest.

Assignment
Follow the Coding Tutorial to write a GitHub Actions workflow that runs the shop's tests on Python 3.13 on every push.

Hint
Indentation is the structure, and it must be spaces: the step items start 6 spaces in with a dash, with: sits 8 spaces in under its uses, and python-version 10. Write the version in quotes, '3.13', so YAML keeps it as text.