Function question

cli/src/cli/readline.ts:20–63

(prompt: string, options: QuestionOptions = {})

 * Returns `null` when stdin reaches EOF (e.g. Ctrl-D on an empty line).
 */
export function question(prompt: string, options: QuestionOptions = {}): Promise<string | null> {
    const enableHistory = options.enableHistory ?? false;
    const task = chain.then(() => askQuestion(prompt, enableHistory));
    chain = task.catch(() => undefined);
    return task;
}

/**
 * Prompt once, recreating the readline interface after job-control resume (Ctrl-Z / fg).
 * Suspending clobbers TTY settings; Node's readline does not recover unless the interface
 * is restarted on SIGCONT.
 */
async function askQuestion(prompt: string, enableHistory: boolean): Promise<string | null> {
    while (true) {
        const rl = readline.createInterface({
            input: process.stdin,
            output: process.stdout,
            ...(enableHistory ? { history: [...history], historySize } : {}),
        });

        const sigcontAbortController = new AbortController();

        rl.on('SIGCONT', () => {
            sigcontAbortController.abort();
            rl.close();
        });

        const eof = new Promise<null>((resolve) => {
            rl.once('close', () => {
                if (!sigcontAbortController.signal.aborted) {
                    resolve(null);
                }
            });
        });

        try {
            const answer = await Promise.race([rl.question(prompt, { signal: sigcontAbortController.signal }), eof]);

            if (answer === null) {
                return null;
            }

            if (enableHistory) {
                syncHistory(rl, answer);
            }
            return answer;
        } catch (error: unknown) {