# Test Client - `TestClient`

You can use the `TestClient` class to test FastAPI applications without creating an actual HTTP and socket connection, just communicating directly with the FastAPI code.

Read more about it in the [FastAPI docs for Testing](https://fastapi.tiangolo.com/tutorial/testing/).

You can import it directly from `fastapi.testclient`:

```python
from fastapi.testclient import TestClient
```

 * ```
 *
 * If any other extension or parameter is specified, then [unknownValues] will be true. Such
 * responses should be refused as their web socket extensions will not be understood.
 *
 * Note that [java.util.zip.Deflater] is hardcoded to use 15 bits (32 KiB) for
 * `client_max_window_bits` and [java.util.zip.Inflater] is hardcoded to use 15 bits (32 KiB) for

          // This is an HTTP/1 upgrade. (This case includes web socket upgrades.)
          isUpgradeRequest && isUpgradeResponse -> {
            response
              .newBuilder()
              .body(
                UnreadableResponseBody(
                  response.body.contentType(),
                  response.body.contentLength(),
                ),
              ).socket(exchange.upgradeToSocket())
              .build()

 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package okhttp3.internal.connection

import java.net.Socket
import java.util.concurrent.ConcurrentLinkedQueue
import java.util.concurrent.TimeUnit
import okhttp3.Address
import okhttp3.ConnectionPool
import okhttp3.Route
import okhttp3.internal.closeQuietly

    hostname: String?,
    protocols: List<Protocol>,
  ) {
    // No TLS extensions if the socket class is custom.
    socketAdapters
      .find { it.matchesSocket(sslSocket) }
      ?.configureTlsExtensions(sslSocket, hostname, protocols)
  }

  override fun getSelectedProtocol(sslSocket: SSLSocket): String? =
    // No TLS extensions if the socket class is custom.

import java.net.SocketAddress;
import jnr.unixsocket.UnixSocket;
import jnr.unixsocket.UnixSocketAddress;
import jnr.unixsocket.UnixSocketChannel;

/**
 * Subtype UNIX socket for a higher-fidelity impersonation of TCP sockets. This is named "tunneling"
 * because it assumes the ultimate destination has a hostname and port.
 */
final class TunnelingUnixSocket extends UnixSocket {
  private final File path;

    await websocket.accept()
    await websocket.send_text(pathparam)
    await websocket.send_text(queryparam)
    await websocket.close()


async def ws_dependency():
    return "Socket Dependency"


@router.websocket("/router-ws-depends/")
async def router_ws_decorator_depends(
    websocket: WebSocket, data=Depends(ws_dependency)
):
    await websocket.accept()

   dropped in 2.0.

## Version 1.5.4

_2014-04-14_

 * Drop ALPN support in Android. There's a concurrency bug in all
   currently-shipping versions.
 * Support asynchronous disconnects by breaking the socket only. This should
   prevent flakiness from multiple threads concurrently accessing a stream.

## Version 1.5.3

_2014-03-29_

 * Fix bug where the Content-Length header was not always dropped when

 * limitations under the License.
 */
package okhttp3.internal.http2

import java.io.IOException

/** Thrown when an HTTP/2 stream is canceled without damage to the socket that carries it. */
class StreamResetException(
  @JvmField val errorCode: ErrorCode,

import okhttp3.HttpUrl
import okio.ByteString

/** An HTTP request that came into the mock web server. */
public class RecordedRequest(
  /**
   * The index of the socket connection that carried this request. If two recorded requests share a
   * connection index, they also shared a socket connection.
   */
  public val connectionIndex: Int,
  /**
   * The index of this exchange on its HTTP connection. A request is uniquely identified by the