tokenUrl="/token",
    description="OAuth2PasswordBearer security scheme",
    auto_error=False,
)


@app.get("/items/")
async def read_items(token: Optional[str] = Security(oauth2_scheme)):
    if token is None:
        return {"msg": "Create an account first"}
    return {"token": token}


client = TestClient(app)


def test_no_token():
    response = client.get("/items")

    assert response.json() == {
        "name": "Island In The Moon",
        "price": 12.99,
        "description": "A place to be playin' and havin' fun",
        "tags": ["breater"],
        "tax": None,
    }


def test_openapi_schema(client: TestClient):
    response = client.get("/openapi.json")
    assert response.status_code == 200
    assert response.json() == snapshot(
        {

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * The {@code Immutable} annotation indicates that the object is immutable, i.e.
 * none of its field can be changed.  This also ensures that the type is
 * {@link ThreadSafe}.
 *
 * @see ThreadSafe
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.CLASS)
@ThreadSafe

                It can be a regular `def` function or an `async def` function.
                """
            ),
        ],
        *args: P.args,
        **kwargs: P.kwargs,
    ) -> None:
        """
        Add a function to be called in the background after the response is sent.

        Read more about it in the

import java.util.zip.ZipEntry
import java.util.zip.ZipInputStream

@CompileStatic
@DisableCachingByDefault(because = "Not worth caching")
abstract class ExplodeZipAndFindJars implements TransformAction<TransformParameters.None> {

    @PathSensitive(PathSensitivity.NAME_ONLY)
    @InputArtifact
    abstract Provider<FileSystemLocation> getArtifact()

    @Override
    void transform(TransformOutputs outputs) {

import java.io.PrintWriter;
import java.util.LinkedHashSet;
import java.util.Set;

@NullMarked
@CacheableTask
public abstract class GenerateDefaultImports extends DefaultTask {
    @PathSensitive(PathSensitivity.NONE)
    @InputFile
    public abstract RegularFileProperty getMetaDataFile();

    @OutputFile
    public abstract RegularFileProperty getImportsDestFile();

    /**

from typing import Optional, Union

from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: Optional[str] = None


class ExtendedItem(Item):
    age: int


@app.post("/items/")
def save_union_different_body(item: Union[ExtendedItem, Item]):
    return {"item": item}


client = TestClient(app)

from fastapi import APIRouter, FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Invoice(BaseModel):
    id: str
    title: Optional[str] = None
    customer: str
    total: float


class InvoiceEvent(BaseModel):
    description: str
    paid: bool


class InvoiceEventReceived(BaseModel):
    ok: bool

终于，我们英雄（hero）的身份得到了保护！ 🥷

它还重新声明了 `id: int` 。这样我们便与 API 客户端建立了一种**约定**，使他们始终可以期待 `id` 存在并且是一个整数 `int`（永远不会是 `None` ）。

/// tip

确保返回模型始终提供一个值并且始终是 `int` （而不是 `None` ）对 API 客户端非常有用，他们可以在这种确定性下编写更简单的代码。

此外，**自动生成的客户端**将拥有更简洁的接口，这样与您的 API 交互的开发者就能更轻松地使用您的 API。😎

///

`HeroPublic` 中的所有字段都与 `HeroBase` 中的相同，其中 `id` 声明为 `int` （不是 `None` ）：

* `id`
* `name`
* `age`
* `secret_name`

import subprocess

from playwright.sync_api import Playwright, sync_playwright


# Run playwright codegen to generate the code below, copy paste the sections in run()
def run(playwright: Playwright) -> None:
    browser = playwright.chromium.launch(headless=False)
    # Update the viewport manually
    context = browser.new_context(viewport={"width": 960, "height": 1080})
    page = context.new_page()
    page.goto("http://localhost:8000/docs")