When I run my application, it writes to /tmp/test/:

```bash
    ゝ<(((˚> @conness:~/servant-typescript [main] λ file /tmp/test/client.ts
    /tmp/test/client.ts: Java source, ASCII text
    ゝ<(((˚> @conness:~/servant-typescript [main] λ file /tmp/test/client.d.ts
    /tmp/test/client.d.ts: ASCII text
    ゝ<(((˚> @conness:~/servant-typescript [main] λ
```

The `rootDir` variable isn't referenced, so I suspect it's probably what was intended here.