The “Books” API app - building an API testing framework in Python

Disclaimer:
This app is intended as a practice app for a testing workshop, so I took some shortcuts. ;-)

Setup & installation

If you run into any issues with the steps below, please let me know at j19sch@gmail.com.

Python and VirtualEnv

• Install Python 3.6 or higher
  • Instructions: https://ehmatthes.github.io/pcc/chapter_01/README.html (no need to install Geany or Sublime Text)
• Install virtualenv. Virtualenv allows you to create an isolated Python environment, with full control over which Python version to use and which Python packages to install.
  • If you have only Python 3 installed: pip install --user virtualenv.
  • If you have Python 2 and Python 3 installed (likely if you use mac or linux), run pip3 install --user virtualenv instead.
  • If you need to figure out what you have installed, you can run python --version and/or python3 --version from the command line.

Download this repo

• Download this repository by clicking the green Code button at the top (make sure you update to
  the latest version right before the workshop) and unzip it. Or if you’re familiar with git, fork this repository.

Create and activate a Python virtual environment

We will be using this virtual environment both for running the test app, and for running the code your
write during the exercises.

• Open a terminal and go into the directory containing the repository files. Important: all commands in this README assume you are in this directory.
• Create a virtual python environment
  • Note that this will create the virtual environment in the current directory, so double-check you are in the directory
    containing the files from the repository.
  • If you have only Python 3 installed: python -m virtualenv venv.
  • If you have both Python 2.7 and Python 3 installed: python3 -m virtualenv -p python3 venv.
• Activate the virtualenv (linux, mac: source venv/bin/activate) or (win: venv\Scripts\activate)
  • Note that once the virtual environment is active, python and pip will be the Python 3 versions, since that is how we set up the virtual environment.
    So for the rest of the instructions it doesn’t matter if you also have Python 2 installed, since we run everything in our virtual Python 3 environment.
• Once you’re done with the virtual environment (i.e. no longer want to play around with the code and the exercises), type deactivate
  to deactivate it. Or close the terminal in which the virtual environment runs.

Install the required libraries

Important: perform the steps below with your virtual environment activated.

• Open the requirements.txt and uncomment either the gunicorn or waitress line depending on your OS
• Install requirements.txt (pip install -r requirements.txt)

Running the app

Important: perform the steps below with your virtual environment activated.

• linux, mac: gunicorn api_app.src.app or win: waitress-serve --port=8000 api_app.src.app:app
• smoke test by using your browser to go to localhost:8000/knockknock
• the easiest way to restart the app is to kill the process (ctrl/cmd+c) and start it again

Docker

If you have Docker installed, you can also run the app in a Docker container:

• build: docker build -f api_app/Dockerfile -t api-app .
• run: docker run -p 80:80 api-app
• smoke test by using your browser to go to localhost:80/knockknock

Advanced text editor

• Any advanced text editor with the following features will do:
  • syntax highlighting (easier to read)
  • word completion (avoids typos in names of variables, functions and methods)
• If you’re note sure which one to use, Visual Studio Code is a good choice: https://code.visualstudio.com/
  • You can find VS Code’s Python plugin here: https://marketplace.visualstudio.com/items?itemName=ms-python.python
  • To tell VS Code to use the interpreter in your virtual environment: https://code.visualstudio.com/docs/python/environments#_select-and-activate-an-environment
  • To enable autosave: https://code.visualstudio.com/docs/editor/codebasics#_save-auto-save
• If you want more of an IDE, PyCharm is an great option:
  • To tell PyCharm to use the interpreter in your virtual environment: https://www.jetbrains.com/help/pycharm/configuring-python-interpreter.html
  • To tell PyCharm to use pytest to run tests: https://www.jetbrains.com/help/pycharm/pytest.html#enable-pytest

Exercises (./exercises)

See ./exercises/README.md for more information about the exercises.

Reference materials

• API documentation for the app: API-docs.md
• Python cheatsheet
  https://github.com/ehmatthes/pcc/releases/download/v1.0.0/beginners_python_cheat_sheet_pcc.pdf
• Requests:
  http://docs.python-requests.org/en/master/
• Pytest:
  https://docs.pytest.org/en/latest/contents.html and https://docs.pytest.org/en/latest/reference.html

Extras (./extras)

This directory contains:

• next steps to extend the framework
• the same test implemented using different tools, e.g. behave and tavern
• a README.md with further details

Further reading

More Pytest

• Pytest reference https://docs.pytest.org/en/latest/reference.html
• Pytest Quick Start Guide - Bruno Oliveira
  https://www.packtpub.com/web-development/pytest-quick-start-guide
• Python Testing with pytest: Simple, Rapid, Effective, and Scalable - Brian Okken
  https://pragprog.com/book/bopytest/python-testing-with-pytest

More Python

• Python koans: https://github.com/gregmalcolm/python_koans
• Raymond Hettinger - Transforming Code into Beautiful, Idiomatic
  Python https://www.youtube.com/watch?v=OSGv2VnC0go
• James Powell - So you want to be a Python expert? https://www.youtube.com/watch?v=cKPlPJyQrt4

Acknowledgements

• Mark Winteringham (@2bittester): restful-booker as inspiration
  (https://github.com/mwinteringham/restful-booker)
• Eric Matthes for the Python Crash Course materials cheatsheet from the Python Crash Course
  (https://ehmatthes.github.io/pcc/cheatsheets/README.html)
• Elizabeth Zagroba: tried it. More stuff works and is spelled correctly now.
• Everyone contributing to pytest, requests, falcon