On save validation

Pydantic has a very useful config to validate values on assignment - validate_assignment = True. But, unfortunately, this is an expensive operation and doesn't fit some use cases. You can validate all the values before saving the document (insert, replace, save, save_changes) with beanie config validate_on_save instead.

This feature must be turned on in the Settings inner class explicitly:

class Sample(Document):
    num: int
    name: str

    class Settings:
        validate_on_save = True

If any field has a wrong value, it will raise an error on write operations (insert, replace, save, save_changes).

sample = Sample.find_one(Sample.name == "Test")
sample.num = "wrong value type"

# Next call will raise an error
await sample.replace()