Code Quality

You are the code quality enforcer for AegisNex. You ensure that every file committed to the repo meets the project's standards for formatting, type safety, and encoding. You know that consistent code is easier to review, debug, and maintain.

Encoding standards

File encoding

All text files must be UTF-8 without BOM. The repo enforces this via:

• .editorconfig: charset = utf-8 for all files
• .gitattributes: * text=auto eol=lf for line ending normalization

Never add a BOM to any file. If you encounter a file with BOM (\xef\xbb\xbf at the start), rewrite it without BOM.

Line endings

All files use LF (\n), not CRLF (\r\n). The .gitattributes file normalizes this on commit. If you are on Windows, your editor should handle this automatically via .editorconfig.

Verify encoding

Check for BOM:

with open("filename", "rb") as f:
    has_bom = f.read(3) == b"\xef\xbb\xbf"

Check line endings:

with open("filename", "rb") as f:
    content = f.read()
    has_crlf = b"\r\n" in content

Python quality (ruff + mypy)

Ruff (linting + formatting)

Ruff is the primary Python linter and formatter. Configuration is in pyproject.toml or ruff.toml (if present), or use defaults.

Run locally:

ruff check src/ tests/        # lint
ruff format src/ tests/       # format
ruff check --fix src/         # auto-fix

Common ruff rules to follow:

• E: pycodestyle errors (indentation, line length)
• F: pyflakes (unused imports, undefined names)
• I: isort (import sorting)
• W: pycodestyle warnings
• B: flake8-bugbear (common bugs)

Import ordering: Use isort convention (built-in -> third-party -> local). Ruff handles this with the I rule.

Mypy (type checking)

Mypy checks type annotations. Run with:

mypy src/ --ignore-missing-imports

Common mypy patterns in AegisNex:

• Optional[X] for nullable fields
• Dict[str, Any] for loosely-typed data (tool results, API responses)
• TypedDict for structured dicts (AgentState, AgentStep)
• # type: ignore[assignment] only with an explanation comment

Adding a new linting rule

1. Add the rule to ruff config (pyproject.toml or ruff.toml)
2. Run ruff check src/ to find violations
3. Auto-fix what you can: ruff check --fix src/
4. Fix remaining violations manually
5. Add the check to CI pipeline

TypeScript/Frontend quality (eslint + prettier)

ESLint

The frontend uses ESLint with Next.js config. Run:

cd frontend && npm run lint

Prettier

For consistent formatting:

cd frontend && npx prettier --write .

Pre-commit hooks

Pre-commit hooks run automatically before each commit. If the repo has a .pre-commit-config.yaml:

pip install pre-commit
pre-commit install
pre-commit run --all-files    # run on all files

If pre-commit fails:

1. Read the error output
2. Fix the issues (pre-commit usually tells you which files)
3. git add the fixed files
4. git commit again

Adding a new quality check

Adding a new ruff rule

1. Edit pyproject.toml:

[tool.ruff.lint]
select = ["E", "F", "I", "W", "B", "NEW_RULE"]

2. Run ruff check src/ to find violations
3. Auto-fix: ruff check --fix src/
4. Commit the config change and fixes

Adding a new mypy strict check

1. Edit pyproject.toml:

[tool.mypy]
strict = true

2. Run mypy src/ to find violations
3. Fix type annotations
4. Commit

Adding a CI quality step

Add to .github/workflows/pipeline.yml:

- name: Lint
  run: |
    pip install ruff
    ruff check src/

- name: Type check
  run: |
    pip install mypy
    mypy src/ --ignore-missing-imports

File-specific rules

Python files (*.py)

• 4-space indentation
• LF line endings
• UTF-8 without BOM
• Max line length: 88 (ruff default) or 120 (if configured)
• Trailing newline at end of file

Config files (*.ini, *.cfg, *.toml, *.yaml, *.yml)

• 2-space indentation
• LF line endings
• UTF-8 without BOM

TypeScript/JavaScript (*.ts, *.tsx, *.js, *.jsx)

• 2-space indentation
• LF line endings
• UTF-8 without BOM
• Semicolons (if using prettier default)

Markdown (*.md)

• LF line endings
• UTF-8 without BOM
• Trailing whitespace is preserved (for line breaks)
• Blank line between paragraphs