from typing import List, Union

from fastapi import FastAPI, UploadFile
from fastapi._compat import (
    ModelField,
    Undefined,
    _get_model_config,
    is_bytes_sequence_annotation,
    is_uploadfile_sequence_annotation,
)
from fastapi.testclient import TestClient
from pydantic import BaseConfig, BaseModel, ConfigDict
from pydantic.fields import FieldInfo

from .utils import needs_pydanticv1, needs_pydanticv2

        new_field.key_field = create_cloned_field(  # type: ignore[attr-defined]
            field.key_field,  # type: ignore[attr-defined]
            cloned_types=cloned_types,
        )
    new_field.validators = field.validators  # type: ignore[attr-defined]
    new_field.pre_validators = field.pre_validators  # type: ignore[attr-defined]
    new_field.post_validators = field.post_validators  # type: ignore[attr-defined]

        const containerStyle = getComputedStyle(this.container);
        this.container.style.width = containerStyle.width !== '0px' ?
            containerStyle.width : undefined;
        this.container.style.minHeight = containerStyle.height !== '0px' ?
            containerStyle.height : undefined;

        this.container.setAttribute('data-termynal', '');
        this.container.innerHTML = '';
        for (let line of this.lines) {

        test: str

    dq = deque([Model(test="test")])

    assert jsonable_encoder(dq)[0]["test"] == "test"


@needs_pydanticv2
def test_encode_pydantic_undefined():
    data = {"value": Undefined}

!!! info
    To send data, you should use one of: `POST` (the more common), `PUT`, `DELETE` or `PATCH`.

    Sending a body with a `GET` request has an undefined behavior in the specifications, nevertheless, it is supported by FastAPI, only for very complex/extreme use cases.

If you want to secure your API, there are several better things you can do, for example:

* Make sure you have well defined Pydantic models for your request bodies and responses.
* Configure any required permissions and roles using dependencies.
* Never store plaintext passwords, only password hashes.

And it can also be used by yourself, to debug, check and test the same application.

## The `password` flow

Now let's go back a bit and understand what is all that.

The `password` "flow" is one of the ways ("flows") defined in OAuth2, to handle security and authentication.

OAuth2 was designed so that the backend or API could be independent of the server that authenticates the user.

    * And validators allow complex data schemas to be clearly and easily defined, checked and documented as JSON Schema.
    * You can have deeply **nested JSON** objects and have them all validated and annotated.
* **Extensible**:
    * Pydantic allows custom data types to be defined or you can extend validation with methods on a model decorated with the validator decorator.

## Development

By the time I started creating **FastAPI** itself, most of the pieces were already in place, the design was defined, the requirements and tools were ready, and the knowledge about the standards and specifications was clear and fresh.

## Future

By this point, it's already clear that **FastAPI** with its ideas is being useful for many people.

    You can use a closing code from the <a href="https://tools.ietf.org/html/rfc6455#section-7.4.1" class="external-link" target="_blank">valid codes defined in the specification</a>.

### Try the WebSockets with dependencies

If your file is named `main.py`, run your application with:

<div class="termy">

```console
$ fastapi dev main.py