Running PyTest in GitHub Actions

Introduction

Running PyTest in GitHub Actions helps you automatically test your Python code every time you make changes. This keeps your code working well without manual checks.

You want to check your Python code for errors after every update.

You want to make sure new code does not break existing features.

You want to run tests automatically when you push code to GitHub.

You want to share test results with your team easily.

You want to save time by automating testing instead of running tests manually.

Syntax

PyTest

name: Python PyTest Workflow

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.x'
      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install pytest
      - name: Run tests
        run: pytest

This YAML file defines a GitHub Actions workflow to run PyTest.

It triggers on code pushes and pull requests.

Examples

This example runs tests only on push events using Python 3.9.

PyTest

on: push

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-python@v4
        with:
          python-version: '3.9'
      - run: pip install pytest
      - run: pytest

This example runs tests on pull requests to the main branch and installs dependencies from a requirements file.

PyTest

on:
  pull_request:
    branches: [ main ]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-python@v4
        with:
          python-version: '3.10'
      - run: pip install -r requirements.txt
      - run: pytest

Sample Program

This workflow runs PyTest automatically on every push or pull request using Python 3.12.

PyTest

name: Python PyTest Workflow

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.12'
      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install pytest
      - name: Run tests
        run: pytest

Important Notes

Make sure your test files and functions follow PyTest naming conventions (files start with test_, functions start with test_).

You can add more dependencies to the install step if your project needs them.

Use runs-on: ubuntu-latest to run tests on a Linux machine in GitHub Actions.

Summary

GitHub Actions can run PyTest automatically on code changes.

Define a workflow YAML file with steps to set up Python, install PyTest, and run tests.

This helps catch errors early and keeps your code healthy.

Practice

1. What is the main purpose of running pytest in a GitHub Actions workflow?

easy

A. To automatically test code changes and catch errors early

B. To deploy the application to production

C. To create a backup of the repository

D. To format the code automatically

Solution

1. Step 1: Understand pytest's role in GitHub Actions CI

   PyTest is a testing tool that checks if code works correctly. GitHub Actions runs tests automatically on code changes to catch errors early.

2. Final Answer:

   To automatically test code changes and catch errors early -> Option A

3. Quick Check:

   PyTest in GitHub Actions = automatic testing [OK]

Hint: PyTest in GitHub Actions runs tests automatically [OK]

Common Mistakes:

• Confusing testing with deployment
• Thinking PyTest formats code
• Assuming it creates backups

2. Which of the following is the correct step to install PyTest in a GitHub Actions workflow YAML file?

easy

A. run: apt-get install pytest

B. run: npm install pytest

C. run: pip install pytest

D. run: brew install pytest

Solution

1. Step 1: Identify the package manager and correct install command for PyTest

   PyTest is a Python package installed using pip. The correct command is run: pip install pytest.

2. Final Answer:

   run: pip install pytest -> Option C

3. Quick Check:

   Python packages use pip install [OK]

Hint: Use pip to install Python packages like PyTest [OK]

Common Mistakes:

• Using npm which is for JavaScript
• Using apt-get or brew which are system package managers
• Missing the pip command

3. Given this GitHub Actions step in a workflow YAML file:

  - name: Run tests
    run: pytest tests/

What will happen when this step runs?

medium

A. PyTest will deploy the tests to a server

B. PyTest will install dependencies before running tests

C. PyTest will create a test report file automatically

D. PyTest will run all tests inside the tests/ directory

Solution

1. Step 1: Analyze the pytest tests/ command and default behavior

   pytest tests/ runs all test files inside the tests/ folder by default but does not install dependencies or deploy code.

2. Final Answer:

   PyTest will run all tests inside the tests/ directory -> Option D

3. Quick Check:

   pytest tests/ runs tests in tests/ folder [OK]

Hint: pytest <folder> runs tests in that folder [OK]

Common Mistakes:

• Thinking PyTest installs dependencies
• Assuming PyTest deploys code
• Expecting automatic report file creation

4. You wrote this GitHub Actions step:

- name: Run tests
  run: py.test

But the workflow fails with "command not found" error. What is the likely cause?

medium

A. The command should be pytest not py.test

B. PyTest is not installed before running the tests

C. The tests directory is missing

D. GitHub Actions does not support running tests

Solution

1. Step 1: Diagnose the command not found error for py.test

   PyTest must be installed first; both pytest and py.test work if installed.

2. Final Answer:

   PyTest is not installed before running the tests -> Option B

3. Quick Check:

   Install PyTest before running tests [OK]

Hint: Always install PyTest before running it in workflow [OK]

Common Mistakes:

• Assuming command spelling is wrong
• Ignoring PyTest installation step
• Blaming GitHub Actions for test failures

5. You want to create a GitHub Actions workflow that runs PyTest on Python 3.10 and 3.11 versions. Which YAML snippet correctly sets up the Python versions and runs PyTest?

hard

A. jobs:
test:
runs-on: ubuntu-latest
strategy:
matrix:
python-version: [3.10, 3.11]
steps:
- uses: actions/checkout@v3
- name: Set up Python
uses: actions/setup-python@v4
with:
python-version: ${{ matrix.python-version }}
- name: Install dependencies
run: pip install pytest
- name: Run tests
run: pytest

B. jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Set up Python
uses: actions/setup-python@v4
with:
python-version: 3.10
- name: Install dependencies
run: pip install pytest
- name: Run tests
run: pytest
- name: Set up Python
uses: actions/setup-python@v4
with:
python-version: 3.11
- name: Run tests
run: pytest

C. jobs:
test:
runs-on: ubuntu-latest
strategy:
matrix:
python-version: [3.10, 3.11]
steps:
- uses: actions/checkout@v3
- name: Install dependencies
run: pip install pytest
- name: Set up Python
uses: actions/setup-python@v4
with:
python-version: ${{ matrix.python-version }}
- name: Run tests
run: pytest

D. jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Set up Python
uses: actions/setup-python@v4
with:
python-version: 3.10
- name: Run tests
run: pytest

Solution

1. Step 1: Identify YAML with matrix strategy and correct step order for multi-version testing

   Use strategy.matrix to run on 3.10/3.11; checkout, then setup Python with ${{ matrix.python-version }}, install pytest, run tests.

2. Final Answer:

   YAML snippet with matrix strategy and correct step order -> Option A

3. Quick Check:

   Matrix + setup-python + install + run = jobs: test: runs-on: ubuntu-latest strategy: matrix: python-version: [3.10, 3.11] steps: - uses: actions/checkout@v3 - name: Set up Python uses: actions/setup-python@v4 with: python-version: ${{ matrix.python-version }} - name: Install dependencies run: pip install pytest - name: Run tests run: pytest [OK]

Hint: Use matrix for versions, setup-python before install and test [OK]

Common Mistakes:

• Not using matrix for multiple versions
• Installing PyTest before setting Python version
• Repeating setup-python steps instead of matrix