return { url: `ws://127.0.0.1:${port}` };

}

function createSignal() {

let resolve: (() => void) | undefined;

const promise = new Promise<void>((next) => {

resolve = next;

});

if (!resolve) {

throw new Error("Expected frame signal resolver to be initialized");

}

return { promise, resolve };

}

describe("createRealtimeTranscriptionWebSocketSession", () => {

it("flushes queued binary audio after an open-ready connection", async () => {

const frames: Buffer[] = [];

let resolveFrames!: () => void;

const framesReady = new Promise<void>((resolve) => {

resolveFrames = resolve;

});

const framesReady = createSignal();

const server = await createRealtimeServer({

onBinary: (payload) => {

frames.push(payload);

if (Buffer.concat(frames).toString() === "queuedafter") {

resolveFrames();

framesReady.resolve();

}

},

});

session.sendAudio(Buffer.from("queued"));

await session.connect();

session.sendAudio(Buffer.from("after"));

await framesReady;

await framesReady.promise;

expect(Buffer.concat(frames).toString()).toBe("queuedafter");

expect(session.isConnected()).toBe(true);

session.close();

});

it("lets providers mark ready after a JSON handshake", async () => {

const frames: unknown[] = [];

let resolveFrames!: () => void;

const framesReady = new Promise<void>((resolve) => {

resolveFrames = resolve;

});

const framesReady = createSignal();

const server = await createRealtimeServer({

initialEvent: { type: "session.created" },

onText: (payload) => {

frames.push(payload);

if (frames.length === 2) {

resolveFrames();

framesReady.resolve();

}

},

});

session.sendAudio(Buffer.from("queued"));

await session.connect();

await framesReady;

await framesReady.promise;

expect(frames).toEqual([

{ type: "session.update" },

{ type: "input_audio.append", audio: Buffer.from("queued").toString("base64") },