Automate Code Clean-up using pre-commits

auto_clean_up.md

Python

1. Install pre-commit: pip install pre-commit
2. Add pre-commit to requirements.txt (or requirements-dev.txt)
3. Define .pre-commit-config.yaml with the hooks you want to include
4. Execute pre-commit install to install git hooks in your .git/ directory

The YAML file configures the sources where the hooks will be taken from. In our case, flake8’s already been included in this framework so we just need to specify its id. On the other hand, we need to define where to source black using few lines of code. Below is a sample .pre-commit-config.yaml file that I use in my project:

repos:
-   repo: https://github.com/psf/black
    rev: stable
    hooks:
    - id: black
      language_version: python3.6
-   repo: https://gitlab.com/pycqa/flake8
    rev: 3.7.9
    hooks:
    - id: flake8

Code Formatter: Black

These are my opinions on how to format my Python code:

1. Unlike in PEP8, code length is 120 characters, not 80. Because we use 1080p monitors.
2. Use of double-quotes than single-quotes in strings.
3. If there are many function args, each arg will be wrapped per line.

[tool.black]
line-length = 120
include = '\.pyi?$'
exclude = '''
/(
    \.git
  | \.hg
  | \.mypy_cache
  | \.tox
  | \.venv
  | _build
  | buck-out
  | build
  | dist
)/
'''

Alternative to black is autopep8.

Code checker: Flake8 (think Grammer check)

In order for black to work nicely with flake8 (or prevent it from spewing out various errors and warnings), we need to list down some error codes to ignore. Feel free to change the ignore list.

You can check my .flake8 configuration below:

[flake8]
ignore = E203, E266, E501, W503, F403, F401
max-line-length = 79
max-complexity = 18
select = B,C,E,F,W,T4,B9

JavaScript/TypeScript

@todo

PHP

Needs PHP8.1 and Composer

composer require --dev phpstan/phpstan
composer require --dev squizlabs/php_codesniffer

or via compose.json

{
  "require-dev":{
    "phpstan/phpstan": "^1.3",
    "squizlabs/php_codesniffer": "^3.6"
  }
}

Setting up the pre-hook

Open .git/hooks/pre-commit file:

#!/usr/bin/env bash

function __run() #(step, name, cmd)
{
    local color output exitcode

    printf "[%s] %-20s" "$1" "$2"
    output=$(eval "$3" 2>&1)
    exitcode=$?

    if [[ 0 == $exitcode || 130 == $exitcode ]]; then
        echo -e "OK!"
    else
        echo -e "Not OK!\n\n$output"
        exit 1
    fi
}

modified="git diff --diff-filter=M --name-only --cached  | grep \".php$\""
ignore="resources/lang,resources/views,bootstrap/helpers,database/migrations,bin"
phpcs="vendor/bin/phpcs --report=code --colors --report-width=80 --standard=PSR2 --ignore=${ignore}"

__run "1/3" "php lint" "${modified} | xargs -r php -l"
__run "2/3" "code sniffer" "${modified} | xargs -r ${phpcs}"
__run "3/3" "phpstan" "${modified} | xargs -r vendor/bin/phpstan analyse"

References

• https://ljvmiranda921.github.io/notebook/2018/06/21/precommits-using-black-and-flake8/
• https://technotzz.wordpress.com/2021/12/31/how-to-setup-git-commit-pre-hook-for-php/