Function invokeEngine

src/engine.ts:359–415

(engine: ResolvedEngine, prompt: string, opts: InvokeOptions = {})

 * EOF immediately so the child proceeds with just the prompt arg.
 */
export function invokeEngine(engine: ResolvedEngine, prompt: string, opts: InvokeOptions = {}): string {
  const { bin, args } = engine.config;
  const timeout   = opts.timeout   ?? DEFAULT_TIMEOUT;
  const maxBuffer = opts.maxBuffer ?? DEFAULT_MAXBUF;

  const result = spawnSync(bin, args(prompt, engine), {
    input: '',              // EOF on stdin — do not inherit parent stdin
    timeout,
    maxBuffer,
    encoding: 'buffer',
  });

  const stderrBuf = result.stderr ?? Buffer.alloc(0);
  const stderr    = redactSecrets(tailString(stderrBuf, STDERR_TAIL_BYTES));

  if (result.error) {
    const anyErr = result.error as NodeJS.ErrnoException & { code?: string };
    if (anyErr.code === 'ETIMEDOUT') {
      throw new EngineInvocationError({
        engine: engine.name, bin, stderr,
        killed: true, code: null, signal: 'SIGTERM', reason: 'timeout',
        message: buildMessage(engine.name, 'timeout', stderr, null, 'SIGTERM', timeout),
      });
    }
    if (anyErr.code === 'ERR_CHILD_PROCESS_STDIO_MAXBUFFER') {
      throw new EngineInvocationError({
        engine: engine.name, bin, stderr,
        killed: true, code: null, signal: null, reason: 'maxbuffer',
        message: buildMessage(engine.name, 'maxbuffer', stderr, null, null, timeout),
      });
    }
    throw new EngineInvocationError({
      engine: engine.name, bin,
      stderr: '', killed: false, code: null, signal: null, reason: 'spawn',
      message: buildMessage(engine.name, 'spawn', anyErr.message ?? '', null, null, timeout),
    });
  }

  if (result.signal === 'SIGTERM' && (result.status === null || result.status === 143)) {
    // spawnSync sets .signal='SIGTERM' when the timeout kills the child.
    throw new EngineInvocationError({
      engine: engine.name, bin, stderr,
      killed: true, code: result.status, signal: result.signal, reason: 'timeout',
      message: buildMessage(engine.name, 'timeout', stderr, result.status, result.signal, timeout),
    });
  }

  if (result.status !== 0) {
    throw new EngineInvocationError({
      engine: engine.name, bin, stderr,
      killed: false, code: result.status, signal: result.signal, reason: 'exit',
      message: buildMessage(engine.name, 'exit', stderr, result.status, result.signal, timeout),
    });
  }

  return (result.stdout ?? Buffer.alloc(0)).toString('utf-8').trim();
}