Function drainStdin

src/ink/ink.tsx:1664–1718

(stdin: NodeJS.ReadStream = process.stdin)

 */
/* eslint-disable custom-rules/no-sync-fs -- must be sync; called from signal handler / unmount */
export function drainStdin(stdin: NodeJS.ReadStream = process.stdin): void {
  if (!stdin.isTTY) return;
  // Drain Node's stream buffer (bytes libuv already pulled in). read()
  // returns null when empty — never blocks.
  try {
    while (stdin.read() !== null) {
      /* discard */
    }
  } catch {
    /* stream may be destroyed */
  }
  // No /dev/tty on Windows; CONIN$ doesn't support O_NONBLOCK semantics.
  // Windows Terminal also doesn't buffer mouse reports the same way.
  if (process.platform === 'win32') return;
  // termios is per-device: flip stdin to raw so canonical-mode line
  // buffering doesn't hide partial input from the non-blocking read.
  // Restored in the finally block.
  const tty = stdin as NodeJS.ReadStream & {
    isRaw?: boolean;
    setRawMode?: (raw: boolean) => void;
  };
  const wasRaw = tty.isRaw === true;
  // Drain the kernel TTY buffer via a fresh O_NONBLOCK fd. Bounded at 64
  // reads (64KB) — a real mouse burst is a few hundred bytes; the cap
  // guards against a terminal that ignores O_NONBLOCK.
  let fd = -1;
  try {
    // setRawMode inside try: on revoked TTY (SIGHUP/SSH disconnect) the
    // ioctl throws EBADF — same recovery path as openSync/readSync below.
    if (!wasRaw) tty.setRawMode?.(true);
    fd = openSync('/dev/tty', fsConstants.O_RDONLY | fsConstants.O_NONBLOCK);
    const buf = Buffer.alloc(1024);
    for (let i = 0; i < 64; i++) {
      if (readSync(fd, buf, 0, buf.length, null) <= 0) break;
    }
  } catch {
    // EAGAIN (buffer empty — expected), ENXIO/ENOENT (no controlling tty),
    // EBADF/EIO (TTY revoked — SIGHUP, SSH disconnect)
  } finally {
    if (fd >= 0) {
      try {
        closeSync(fd);
      } catch {
        /* ignore */
      }
    }
    if (!wasRaw) {
      try {
        tty.setRawMode?.(false);
      } catch {
        /* TTY may be gone */
      }
    }
  }
}
/* eslint-enable custom-rules/no-sync-fs */

const CONSOLE_STDOUT_METHODS = ['log', 'info', 'debug', 'dir', 'dirxml', 'count', 'countReset', 'group', 'groupCollapsed', 'groupEnd', 'table', 'time', 'timeEnd', 'timeLog'] as const;