The examples in the repo work, but there are some things missing:

• Documentation needs some improvements.
• Code cleanup is still necessary.
• Mostly - this repo is actually a companion to a blog post explaining this technique, and the blog post has not been published yet.

This is an example of using Property-Based Testing to test a CRUD web application.

The example uses Stateful Testing (AKA model-based testing) to model the correct behavior of the application and find (minimal) sequences of actions that exponse functional bugs.

The testing code is implemented using the excellent Hypothesis Python library.

The server application (code under test) is a python Flask application (see attributions at bottom of README)
The client frontend is implemented in Vue.js (see attributions at bottom of README).

To support gradual learning, this repo has 4 different versions of the code and tests at, and each version contains different bugs and tests with different levels of complexity.

To run the tests, you'll need to (there are exact instructions below - this is so you understand the basic flow)

• Run the client application (also common to all versions).
• Activate a python virtualenv (common to all versions)
• Run the server for a specific version
• Play with the application using the client and reproduce all bugs manually, to get a feeling for how PBT helps you
• Run the tests for the same version Each version has its own directory with its own README file that shows what you can expect the test to show you, and explains the bug.

The version directories are prefixed with a number - start from 01 and move up.

The last version (correct_code) contains the same tests as the previous version, but with the correct code.

Prerequisite: have nvm installed.

Start at repository root directory, and:

cd client
nvm use
npm install
npm run serve

Point your browser to http://localhost:8080

(start at repository root directory)

A virtualenv is a python sandbox, where you can install packages in isolation from the global python installation.
To run the server and tests, you will create a virtualenv, and the scripts that run the server and the tests are aware of the virtualenv and will use it (you don't need to do this yourself).
Pipenv is a helpful tool - a python package that helps manage virtualenvs.

Missing

(this also creates the virtualenv if needed)

./devtools/reinstall_pipenv_packages.sh

cd server_versions/server_01_incorrect_id
./devtools/run_app.sh

(or any of the other directories under server_versions)

Note: the server serves on port 5001 (why? because there's a conflict with apple AirPlay)

cd server_versions/server_01_incorrect_id
./devtools/run_tests.sh

(of course - cd into the same directory as you have for running the server)

The current client and server implementation has originally been copied from (and slightly modified): https://github.com/testdrivenio/flask-vue-crud