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/**
* - 'uninitialized' means we haven't tried to connect yet
* - Promise means it's pending
* - 'failed' means it failed (this is the most common case, where the logger isn't running)
* - WebSocket means it succeeded
*/
let connection: Promise<WebSocket | 'failed'> | WebSocket | 'failed' | 'uninitialized' =
'uninitialized';
/**
* Log a string to a websocket at `localhost:59497`. See `tools/websocket-logger`.
*
* This does nothing if a connection couldn't be established on the first call.
*/
export function logToWebsocket(msg: string) {
if (connection === 'failed') {
return;
}
if (connection === 'uninitialized') {
connection = new Promise(resolve => {
if (typeof WebSocket === 'undefined') {
resolve('failed');
return;
}
const ws = new WebSocket('ws://localhost:59497/optional_cts_websocket_logger');
ws.onopen = () => {
resolve(ws);
};
ws.onerror = () => {
connection = 'failed';
resolve('failed');
};
ws.onclose = () => {
connection = 'failed';
resolve('failed');
};
});
void connection.then(resolved => {
connection = resolved;
});
}
void (async () => {
// connection may be a promise or a value here. Either is OK to await.
const ws = await connection;
if (ws !== 'failed') {
ws.send(msg);
}
})();
}
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