python.pydantic.missing_validators

Correctness Medium

Detects Pydantic models without proper field validators.

Why It Matters

Missing validators:

• Invalid data — Bad values pass validation
• Security issues — Malicious input not sanitized
• Runtime errors — Failures happen later in pipeline

Example

# ❌ Before (no validators)
from pydantic import BaseModel

class User(BaseModel):
    email: str  # Any string accepted!
    age: int  # Negative ages allowed!

# ✅ After (with validators)
from pydantic import BaseModel, EmailStr, Field, validator

class User(BaseModel):
    email: EmailStr
    age: int = Field(ge=0, le=150)

    @validator('email')
    def normalize_email(cls, v):
        return v.lower().strip()

What Unfault Detects

• str fields that should use constrained types
• Numeric fields without bounds
• Missing sanitization validators

Related Rules

• python.fastapi.input_validation