## HTTPX

Даже если **FastAPI** приложение использует обычные функции `def` вместо `async def`, это все равно `async` приложение 'под капотом'.

您已经了解了如何使用 `TestClient` 测试 **FastAPI** 应用程序。但是到目前为止，您只了解了如何编写同步测试，而没有使用 `async` 异步函数。

在测试中能够使用异步函数可能会很有用，比如当您需要异步查询数据库的时候。想象一下，您想要测试向 FastAPI 应用程序发送请求，然后验证您的后端是否成功在数据库中写入了正确的数据，与此同时您使用了异步的数据库的库。

让我们看看如何才能实现这一点。

## pytest.mark.anyio

如果我们想在测试中调用异步函数，那么我们的测试函数必须是异步的。 AnyIO 为此提供了一个简洁的插件，它允许我们指定一些测试函数要异步调用。

## HTTPX

即使您的 **FastAPI** 应用程序使用普通的 `def` 函数而不是 `async def` ，它本质上仍是一个 `async` 异步应用程序。

# Async Tests { #async-tests }

You have already seen how to test your **FastAPI** applications using the provided `TestClient`. Up to now, you have only seen how to write synchronous tests, without using `async` functions.

## HTTPX

Auch wenn Ihre **FastAPI**-Anwendung normale `def`-Funktionen anstelle von `async def` verwendet, handelt es sich darunter immer noch um eine `async`hrone Anwendung.

➖ 💪 ⚙️ 🔁 🔢 👆 💯 💪 ⚠, 🖼, 🕐❔ 👆 🔬 👆 💽 🔁. 🌈 👆 💚 💯 📨 📨 👆 FastAPI 🈸 & ⤴️ ✔ 👈 👆 👩‍💻 ⏪ ✍ ☑ 💽 💽, ⏪ ⚙️ 🔁 💽 🗃.

➡️ 👀 ❔ 👥 💪 ⚒ 👈 👷.

## pytest.mark.anyio

🚥 👥 💚 🤙 🔁 🔢 👆 💯, 👆 💯 🔢 ✔️ 🔁. AnyIO 🚚 👌 📁 👉, 👈 ✔ 👥 ✔ 👈 💯 🔢 🤙 🔁.

## 🇸🇲

🚥 👆 **FastAPI** 🈸 ⚙️ 😐 `def` 🔢 ↩️ `async def`, ⚫️ `async` 🈸 🔘.

# "/path/bar". This script uses "gsutil rsync" instead, which acts on directory
# contents. About arguments to gsutil:
# "gsutil -m rsync" runs in parallel.
# "gsutil rsync -r" is recursive and makes directories work.
# "gsutil rsync -d" is "sync and delete files from destination if not present in source"

DOWNLOADS="$(mktemp -d)"
mkdir -p "$DOWNLOADS"
gsutil -m rsync -r "$TFCI_ARTIFACT_STAGING_GCS_URI" "$DOWNLOADS"

		r = bf
	default:
		return fmt.Errorf("Unsupported format %s", f)
	}
	tarReader := tar.NewReader(r)
	n := 0
	asyncWriters := make(chan struct{}, 16)
	var wg sync.WaitGroup

	var asyncErr error
	var asyncErrMu sync.Mutex
	for {
		if !o.ignoreErrs {
			asyncErrMu.Lock()
			err := asyncErr
			asyncErrMu.Unlock()
			if err != nil {
				return err
			}
		}

	quorum := (len(localDrives) / 2)

	buckets = make([]BucketInfo, 0, 32)
	healBuckets := xsync.NewMapOf[string, VolInfo]()

	// lists all unique buckets across drives.
	if err := listAllBuckets(ctx, localDrives, healBuckets, quorum); err != nil {
		return nil, err
	}

	// include deleted buckets in listBuckets output
	deletedBuckets := xsync.NewMapOf[string, VolInfo]()

	if opts.Deleted {

	trash:   make(map[string]metacache),
}

type metacacheManager struct {
	mu      sync.RWMutex
	init    sync.Once
	buckets map[string]*bucketMetacache
	trash   map[string]metacache // Recently deleted lists.
}

const metacacheMaxEntries = 5000

// initManager will start async saving the cache.
func (m *metacacheManager) initManager() {
	// Add a transient bucket.

            byte[] buffer = new byte[256];
            System.arraycopy(SMBUtil.SMB2_HEADER, 0, buffer, 0, 4);
            // Set up async message fields
            SMBUtil.writeInt4(ServerMessageBlock2.SMB2_FLAGS_ASYNC_COMMAND, buffer, 16); // flags with async
            SMBUtil.writeInt8(789L, buffer, 32); // async ID
            SMBUtil.writeInt8(456L, buffer, 40); // session ID
            return buffer;
        }