Judicious Observant Linting Assistant 🚀

JOLA - Judicious Observant Linting Assistant 🚀

Introduction

Welcome to JOLA, a groundbreaking Python linter!

JOLA stands out in the Python development landscape as it focuses on an often-overlooked yet crucial aspect: Django relationship fields type hinting.

Why JOLA?

JOLA currently fills a critical gap in Django development. The typical Language Server Protocols (LSPs) struggle, especially with relationship fields like ForeignKey and OneToOneField. JOLA not only detects missing type hints in these areas but also offers a --fix option to automatically rectify them.

But that's just the beginning! 🌟 JOLA is set to evolve with more incredible features. Future updates will include capabilities like auto-generating explicit imports, further simplifying and streamlining your Django development process. Stay tuned for these exciting enhancements!

Features

🕵️‍♂️ Detect Missing Type Hints of Relationship Fields

Consider the following Django model:

class Article(models.Model):
    user = models.ForeignKey(User, ...)

In this case, LSPs often can't comprehend what article.user.email means. JOLA detects such instances and helps in maintaining robust type hinting.

🛠️ Automatic Fix with --fix

JOLA doesn't just point out issues; it fixes them! With the --fix option, JOLA can automatically add appropriate type hints, turning your code into:

class Article(models.Model):
    user: models.ForeignKey[User] = models.ForeignKey(User, ...)

Now, your IDE understands exactly what article.user.email refers to!

🔗 Leverage Deep Relationships

JOLA shines in complex scenarios involving nested relationships. For example:

class Profile(models.Model):
    image_url = models.ImageField(...)

class User(models.Model):
    profile: models.OneToOneField[Profile] = models.OneToOneField(Profile, ...)

class Article(models.Model):
    user: models.ForeignKey[User] = models.ForeignKey(User, ...)

Here, JOLA ensures that even deeply nested attributes like article.user.profile.image_url are clearly understood by your language server.

Limitations and Workarounds

While JOLA is powerful, it has its limitations. For instance, when a ForeignKey is not directly defined with the actual model, JOLA cannot automatically fix it:

class Article(models.Model):
    user = models.ForeignKey('users.User', ...)

In such cases, I recommend you a workaround to avoid circular imports and maintain clarity, by manually:

from typing import TYPE_CHECKING, Any

if TYPE_CHECKING:
    from users.models import User
else:
    User = Any

class Article(models.Model):
    user: models.ForeignKey[User] = models.ForeignKey('users.User', ...)

This approach ensures type hinting for language servers without runtime import issues.

Installation

Currently, JOLA is available only for Python 3.9+.

Sadly, JOLA is not yet available on PyPI. I am working on it and this section will be updated once it is available.