expect(result).toEqual(Buffer.from("mp3"));

expect(fetchMock).toHaveBeenCalledOnce();

const [url, init] = fetchMock.mock.calls.at(0) as [string, RequestInit];

const [url, init] = fetchMock.mock.calls[0] as [string, RequestInit];

expect(url).toBe("https://eastus.tts.speech.microsoft.com/cognitiveservices/v1");

expect(init.method).toBe("POST");

const headers = new Headers(init.headers);

});

expect(fetchMock).toHaveBeenCalledOnce();

const [url, init] = fetchMock.mock.calls.at(0) as [string, RequestInit];

const [url, init] = fetchMock.mock.calls[0] as [string, RequestInit];

expect(url).toBe("https://custom.example.com/cognitiveservices/voices/list");

expect(new Headers(init.headers).get("Ocp-Apim-Subscription-Key")).toBe("speech-key");

expect(init.signal).toBeInstanceOf(AbortSignal);