text,

output,

{ voice = "Ryan", language = "en", style = null, utterCommand = "utter" } = {},

) {

const absoluteOutput = resolve(output);

await mkdir(dirname(absoluteOutput), { recursive: true });

const args = [

"speak", "--stdin", "--voice", voice, "--language", language,

"--output", absoluteOutput, "--json",

];

if (style) args.push("--style", style);

return await new Promise((resolvePromise, reject) => {

const child = spawn(utterCommand, args);

let stdout = "";

let stderr = "";

child.stdout.setEncoding("utf8").on("data", chunk => stdout += chunk);

child.stderr.setEncoding("utf8").on("data", chunk => stderr += chunk);

child.on("error", reject);

child.on("close", code => {

let payload;

try {

payload = JSON.parse(stdout);

} catch (error) {

reject(new Error(`Utter returned invalid JSON: ${stdout}\n${stderr}`));

return;

}

if (code !== 0) {

reject(new Error(

`Utter failed (${payload.error?.code}): ` +

`${payload.error?.message}\n${stderr.trim()}`,

));

return;

}

resolvePromise(payload.output);

});

child.stdin.end(text, "utf8");

});