code-quality-talk - Notes:

pre-commit demo:

• Create a new repo directory
• cd dev
• mkdir pre-commit-demo
• cd pre-commit-demo
• git init
• pip3 install pre-commit --user
• pre-commit install
• pre-commit sample-config > .pre-commit-config.yaml
• pre-commit install-hooks

• echo "Hello World    " > hello.txt
  

• git add .
• pre-commit run --all-files (show that it fails)
• git diff (show that it has removed the space that we added)
• pre-commit run --all-files (show that it passes second time)
• truncate -s -1 hello.txt (remove the trailing space from the file)
• pre-commit run --all-files (show that it fails on the end of file fixer)
• pre-commit run --all-files (show that it passes second time)

pre-commit demo on LincolnHack repo:

Basics:

• cd lincolnhack_dd
• git switch spike
• pip3 install pre-commit --user
• git switch -c pre-commit
• pre-commit install

• cat << EoI > .pre-commit-config.yaml
  repos:
    - repo: https://github.com/pre-commit/pre-commit-hooks
      rev: v4.4.0
      hooks:
        - id: check-added-large-files
          args: [‘--maxkb=1024’]
        - id: check-executables-have-shebangs
        - id: check-json
        - id: check-merge-conflict
        - id: check-shebang-scripts-are-executable
        - id: check-symlinks
        - id: check-yaml
          args: ['--unsafe']
        - id: detect-private-key
        - id: end-of-file-fixer
        - id: mixed-line-ending
          args: [--fix=lf]
        - id: trailing-whitespace
        # Python
        - id: check-docstring-first
  EoI
  

• pre-commit install-hooks
• git add .
• pre-commit run --all-files

Python specific:

• Add cspell, black and isort to the .pre-commit-config.yaml

  •   - repo: https://github.com/pycqa/isort
        rev: 5.12.0
        hooks:
          - id: isort
    
      - repo: https://github.com/psf/black
        rev: 23.7.0
        hooks:
          - id: black
            args: ['--line-length', '120']
    

• Copy config for isort to .isort.cfg

  • [settings]
    line_length=120
    lines_after_imports = 2
    force_sort_within_sections=True
    import_heading_future=Futures Imports
    import_heading_stdlib=Standard Library Imports
    import_heading_django=Django Imports
    import_heading_thirdparty=3rd Party Imports
    import_heading_firstparty=App Imports
    import_heading_localfolder=Local Imports
    known_first_party = lincolnhack_dd
    known_django = django
    sections = FUTURE,STDLIB,DJANGO,THIRDPARTY,FIRSTPARTY,LOCALFOLDER
    skip=migrations
    

• Run pre-commit run --all-files
• Add in fixes
• Run pre-commit run --all-files again
• Add cspell to the .pre-commit-config.yaml

  •   - repo: https://github.com/streetsidesoftware/cspell-cli
        rev: v6.31.0
        hooks:
          - id: cspell
    

• Run pre-commit run --all-files
• Add cspell.config.yaml file

  • ---
    allowCompoundWords: true
    languageSettings:
      - caseSensitive: false
        enabled: true
        languageId: en-GB
    dictionaryDefinitions:
      - name: my_words
        path: ./.my_words.txt
        addWords: true
    dictionaries:
      - my_words
    

• Add .my_words.txt file
  • Show how to run specific hooks
  • Add some words to .my_words.txt
  • Show that words are now not flagged
  • Show disabling single line
    • # // cspell:disable-line
  • Highlight spelling mistake and fix it
  • Add changed files

Github Actions demo:

Reusing the LincolnHack demo:

• Create .github/workflows folder
• Create .github/workflows/pre-commit.yml

  • name: pre-commit
    
    on: [push]
    
    jobs:
      build:
        runs-on: ubuntu-latest
        steps:
          - uses: actions/checkout@v3
          - name: Set up Python 3.11
            uses: actions/setup-python@v4
            with:
              python-version: '3.11'
              check-latest: true
              cache: 'pip'
              cache-dependency-path: .github/requirements.txt
          - run: python3 -m pip install -r .github/requirements.txt
          - run: pre-commit install --install-hooks
          - run: pre-commit run --show-diff-on-failure --color=never --all-files
    

• Create .github/requirements.txt

  • pre-commit==3.3.3
    

• Commit and push (Have Github Actions tab open and ready to show)