Internal Docs - wemake-python-styleguide 1.1.0 documentation (original) (raw)

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Here you can find:

  1. How our development process works
  2. How to contribute to the project
  3. How to write new rules
  4. How our internal API looks like

This information will also be helpful if you would like to create your own flake8 plugin.

How to read this documentation

You will need to start from the glossarywhere we define the terms for this project.

Then move to the contributing guide where we specify all technical details about our workflow and tools.

Then you will be ready to dive into our “Creating a new rule tutorial”.

And finally you will need to go through the API reference to cover specific technical questions you will encounter.

Philosophy

  1. Done is better than perfect
  2. However, we pursue perfect software
  3. False negatives over false positives
  4. If you cannot sustain your promise - do not promise
  5. Code must be written for people to read, and only incidentally for machines to execute
  6. Value consistency over syntax-ish readability
  7. Consistent code is more readable than inconsistent
  8. Do not force people to choose, they will make mistakes
  9. Made choices must be respected

Overview

This schema should give you a brief overview of what is happening inside our linter. This is a very simplified architecture that will help you to understand how all components are bound together.

    sequenceDiagram

participant flake8 participant Checker participant Transformation participant Visitor participant Violation

flake8->>Checker: flake8 runs our checker alongside with other plugins Checker->>Transformation: Checker asks to perform different ast transformations before we actually start doing anything Checker->>Visitor: Checker runs all visitors that it is aware of Visitor->>Violation: Visitors raise violations when they find bad code Violation-->>flake8: Raised violations are shown to user by flake8

Architecture overview.

High-level overview of our codebase:

Code organization

We use a layered architecturethat follows this contract:

[importlinter] root_package = wemake_python_styleguide include_external_packages = True

[importlinter:contract:layers] name = Layered architecture of our linter type = layers

containers = wemake_python_styleguide

layers = checker formatter transformations presets visitors violations logic compat options constants types

TODO: provide independence contract for visitors

[importlinter:contract:violation-independence] name = Independence contract for violations (all shall be free!) type = independence

modules = wemake_python_styleguide.violations.system wemake_python_styleguide.violations.naming wemake_python_styleguide.violations.complexity wemake_python_styleguide.violations.consistency wemake_python_styleguide.violations.best_practices wemake_python_styleguide.violations.refactoring wemake_python_styleguide.violations.oop

[importlinter:contract:flake8-independence] name = Independence contract for flake8 API (all shall be free!) type = independence

modules = wemake_python_styleguide.checker wemake_python_styleguide.formatter

[importlinter:contract:api-restrictions] name = Forbids to import anything from dependencies type = forbidden

source_modules = wemake_python_styleguide

forbidden_modules =

Std imports we don't like:

dataclasses

Important direct and indirect dependencies:

flake8

pygments pyflakes pycodestyle mccabe

ignore_imports =

These modules must import from flake8 to provide required API:

wemake_python_styleguide.checker -> flake8 wemake_python_styleguide.formatter -> flake8 wemake_python_styleguide.options.config -> flake8

We disallow direct imports of our dependencies from anywhere, except:

wemake_python_styleguide.formatter -> pygments

[importlinter:contract:subapi-restrictions] name = Forbids to import anything from our sub-API packages type = forbidden

source_modules = wemake_python_styleguide.visitors wemake_python_styleguide.violations wemake_python_styleguide.compat wemake_python_styleguide.logic

forbidden_modules =

Our sub-API parts:

wemake_python_styleguide.options.config wemake_python_styleguide.transformations wemake_python_styleguide.presets

[importlinter:contract:tests-restrictions] name = Explicit import restrictions for tests type = forbidden

source_modules = wemake_python_styleguide

forbidden_modules = tests

Contributing

This section will help you to know all the tools and terms we are using.

Creating a new rule

This tutorial will guide you through the whole process of creating new rules for this linter.

API Reference