This is documentation for the next version of K6. For the latest stable release, go to the latest version.
connect( url, params, callback )
Note
A module with a better and standard API exists.
The new k6/experimental/websockets API partially implements the WebSockets API living standard.
When possible, we recommend using the new API. It uses a global event loop for consistency with other k6 APIs and better performance.
Initiate a WebSocket connection to a remote host.
Calling connect will block the VU finalization until the WebSocket connection is closed. Instead of continuously looping the main function (export default function() { ... }
) over an over, each VU will be halted listening to async events and executing their event handlers until the connection is closed.
The following events can close the connection:
- remote host close event.
- Socket.close().
- k6 VU interruption based on test configuration or CLI commands.
Parameter | Type | Description |
---|---|---|
url | string | Request URL (e.g. “ws://echo.websocket.org”). |
params | object | Params object containing additional request parameters. |
callback | function | The callback function that will be called when the WebSocket connection is initiated. A Socket object will be passed to the function, and this object can be used to set up callbacks etc when things happen on the WebSocket connection |
Returns
Type | Description |
---|---|
Response | HTTP Response object. |
Example
import ws from 'k6/ws';
export default function () {
const url = 'ws://echo.websocket.org';
const resp = ws.connect(url, null, function (socket) {
socket.on('open', function () {
console.log('WebSocket connection established!');
socket.close();
});
});
}