Task List Refactor Based On Clean Architecture In Python

This is a side project aimed at refactor of Task List Kata based on Clean Architecture in Python. This side project is inspired by its Java implementation throughout the course. The refactor steps are referred to the training course taught by Teddy Chen not only for myself to get familiar with the refactor process but also for someone to learn Clean Architecture.

How to set up the development environment?

Poetry is used in this project for dependency management. Please refer to the official site for the various ways to installation. As of proceeding the refactor, this project used Poetry of version 1.8.5.

Once we have Poetry installed in your environment. We could clone the project listed as follows.

$ git clone https://github.com/tsungchih/task-list-refactor-ca.git

We can then create a virtual environment and install the project dependencies by means of Poetry.

$ cd task-list-refactor-ca
$ poetry env use python3.11
$ poetry install

Now we can run tests to verify if the virtual environment is successfully set up.

$ make tests
=> Running pytest
============================= test session starts ==============================
platform darwin -- Python 3.11.10, pytest-8.3.4, pluggy-1.5.0
rootdir: /path/to/task-list-refactor-ca
configfile: pyproject.toml
collected 1 item

tests/test_application.py .                                              [100%]

============================== 1 passed in 0.08s ===============================
==> Running pytest complete

We can definitely run pytest if the make tool is not available in the environment.

$ pytest
============================= test session starts ==============================
platform darwin -- Python 3.11.10, pytest-8.3.4, pluggy-1.5.0
rootdir: /path/to/task-list-refactor-ca
configfile: pyproject.toml
collected 1 item

tests/test_application.py .                                              [100%]

============================== 1 passed in 0.08s ===============================

After all, we can enable the virtual environment utilizing the following command.

$ poetry shell

This project relies on make tool for automating routine tasks during development. We may check which targets are currently supported by executing make listed as follows.

$ make

Usage:
  make <target>

Targets:
  help                 Show help information
  build-pkg            Build Python package
  tests                Run pytest to all the packages in the repository

The above output showed that three targets, help, build-pkg, and tests, are currently supported. We may add more targets in the Makefile to automate some sorts of routine tasks.

After having successfully set up the development environment, we should prepare the environment for pre-commit to work properly.

$ pre-commit install-hooks

We could now run pre-commit against the installed hooks using the following command every time we have staged the changes to the code base.

$ pre-commit run
check python ast...............................................................Passed
check builtin type constructor use.............................................Passed
check for case conflicts.......................................................Passed
debug statements (python)......................................................Passed
mixed line ending..............................................................Passed
trim trailing whitespace.......................................................Passed
fix end of files...............................................................Passed
check yaml.....................................................................Passed
check json.................................................(no files to check)Skipped
check toml.....................................................................Passed
check for added large files....................................................Passed
detect private key.............................................................Passed
Tests should begin with test_*.py..............................................Passed
check for merge conflicts......................................................Passed
pretty format json.........................................(no files to check)Skipped
don't commit to branch.........................................................Passed
Detect hardcoded secrets.......................................................Passed
apply a consistent format to pyproject.toml files..............................Passed
run 'poetry check' for checking pyproject.toml.................................Passed
run `ruff` for Python linting..................................................Passed
run `ruff format for Python formatting`........................................Passed
run `pyright`, a static type checker...........................................Passed
run 'black' on Python code blocks in documentation files.......................Passed
run 'prettier', an opinionated code formatter..................................Passed

Steps For Refactor Of Task List Kata Based On Clean Architecture

The steps of the holistic refactor process are recorded and formed as branches listed as follows.

Branch	Description
refactor/init	Initialize the Python project using Poetry.
refactor/step-1	Add project structure, entities, and value objects.
refactor/step-2	Extract methods in TaskList as services.