model-entity-validator

Model/Entity Validator

Enforces the BaseModel inheritance pattern (UUID primary keys, audit timestamps, soft deletes) for all Django models.

Activation Triggers

This skill activates when:

• Creating new model files
• Modifying existing models
• Mentioning "model", "database", "schema", "table"
• Writing class inheriting from models.Model
• Running migrations
• Discussing data structure

Core Principle: BaseModel Inheritance

NEVER repeat UUID/timestamp fields. All models inherit from BaseModel.

# ❌ WRONG - Repeating fields
class User(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    is_deleted = models.BooleanField(default=False)
    email = models.EmailField()

# ✅ CORRECT - Inherit from BaseModel
import core.models as _core_models

class User(_core_models.BaseModel):
    email = models.EmailField(unique=True)

Validation Process

Step 1: Check if BaseModel Exists

Before any action, check if the project has a BaseModel:

# Search for BaseModel in (in order):
# 1. core/models.py
# 2. shared/models.py
# 3. common/models.py
# 4. {app}/base.py

If BaseModel found: Suggest inheritance (Step 2a) If BaseModel NOT found: Create BaseModel first (Step 2b)

Step 2a: BaseModel Exists - Suggest Inheritance

When seeing:

class Product(models.Model):
    name = models.CharField(max_length=255)

Fix to:

import core.models as _core_models

class Product(_core_models.BaseModel):
    """Product model - inherits id, timestamps, soft delete from BaseModel."""

    name = models.CharField(max_length=255)
    price = models.DecimalField(max_digits=10, decimal_places=2)

    class Meta:
        db_table = 'products'

Step 2b: BaseModel NOT Found - Create It First

If no BaseModel exists, create it:

# core/models.py
import uuid
from django.db import models

class BaseModel(models.Model):
    """
    Abstract base model providing:
    - UUID primary key
    - Automatic timestamps (created_at, updated_at)
    - Soft delete support (is_deleted)

    All models MUST inherit from this class.
    """

    id = models.UUIDField(
        primary_key=True,
        default=uuid.uuid4,
        editable=False
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    is_deleted = models.BooleanField(default=False)

    class Meta:
        abstract = True
        ordering = ['-created_at']

    def soft_delete(self) -> None:
        """Soft delete the record."""
        self.is_deleted = True
        self.save(update_fields=['is_deleted', 'updated_at'])

    def restore(self) -> None:
        """Restore a soft-deleted record."""
        self.is_deleted = False
        self.save(update_fields=['is_deleted', 'updated_at'])


class ActiveManager(models.Manager):
    """Manager that excludes soft-deleted records."""

    def get_queryset(self):
        return super().get_queryset().filter(is_deleted=False)