Software Testing Exercises (Python + pytest)

This repository contains hands-on labs for practicing different kinds of software testing with Python. You’ll write and run unit tests, integration tests, and end-to-end (E2E) tests, and set up continuous testing with GitHub Actions.

Target environment

• Python: 3.10.18
• pytest: 8.4.2

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📂 Repository Structure

.
├── exercise1_unit/          # Pure function testing (math_utils.py)
├── exercise2_integration/   # Module integration (text pipeline: tokenize + sentiment)
├── exercise3_e2e_cli/       # End-to-end CLI tests (calculator app)
├── .github/workflows/       # GitHub Actions workflow for automated testing
└── README.md

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⚙️ Quick Start

# 1) Create and activate a virtual env (recommended)
python3.10 -m venv .venv
source .venv/bin/activate        # Windows (PowerShell): .\.venv\Scripts\Activate.ps1

# 2) Install test tools
python -m pip install -U pip pytest

# 3) Run all tests
pytest -q

Useful flags

• -v (verbose), -vv (extra verbose; shows parameter sets)
• -k "pattern" to run tests by name pattern
• -q quiet mode, -s show print/log output
• --maxfail=1 -x stop at first failure

Examples:

pytest -vv
pytest -k "pipeline and pos"
pytest --maxfail=1 -x

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🧪 Exercises

1) Unit Testing (tiny pure functions)

• Implement and test add, div, clamp in exercise1_unit/math_utils.py.

• Focus on:

  • Happy paths, edge cases, and error handling
  • Parameterized tests
  • Rejecting invalid inputs like NaN, ∞, or non-numeric types

Run:

pytest exercise1_unit

👉 Learning goal: build fast, isolated, deterministic tests.

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2) Integration Testing (compose tiny modules)

• Combine:

  • tokenizer.py → splits text into words
  • sentiment.py → computes sentiment score
  • text_pipeline.py → integrates both via analyze(text)

• Test the pipeline via analyze(text) without mocks.

• Cover mixed positive/negative words, punctuation, numbers, empty strings, emojis.

Run:

pytest exercise2_integration

👉 Learning goal: verify modules work together and contracts between them hold.

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3) End-to-End (E2E) Testing (CLI)

• Test a CLI calculator (exercise3_e2e_cli/calculator.py) by running it as a subprocess.
• Feed input commands (e.g., add 5 10) and assert exact output.
• Cover valid commands, errors (div by 0, bad input), and boundary behavior.

Run:

pytest -vv exercise3_e2e_cli

👉 Learning goal: simulate real user interactions and validate the whole system.

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4) End-to-End UI Testing (Streamlit + Cypress)

• This exercise replaces the CLI E2E with a real UI: a tiny Streamlit app tested in a real browser via Cypress.
• More details refer to the README.md in exercise4_e2e_streamlit

👉 Learning goal: simulate user interface interactions and validate the whole system.

📈 Code Coverage

1) Install

pip install pytest-cov

2) Run with coverage (local)

Common commands:

# Generate HTML and XML reports
pytest --cov=. --cov-report=html --cov-report=xml:coverage.xml

Open the HTML report in your browser:

• macOS

  open htmlcov/index.html

• Windows (PowerShell / CMD)

  start htmlcov\index.html

• Linux

  xdg-open htmlcov/index.html

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🧱 Typical Layout (by exercise)

exercise1_unit/
  math_utils.py
  test_math_utils.py

exercise2_integration/
  tokenizer.py
  sentiment.py
  text_pipeline.py
  test_text_pipeline.py

exercise3_e2e_cli/
  calculator.py
  test_e2e_cli.py

exercise4_e2e_streamlit/

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🎯 Learning Outcomes

By completing these exercises, you will:

• Understand the test pyramid: unit → integration → E2E
• Write clear, maintainable, and reliable tests
• See how testing fits into real-world industry workflows
• Gain confidence using pytest and GitHub Actions for automation

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