### Some Markdown File

Here's a code segment. It should be emitted to fib.js.

```javascript
// fib.js

let fib = (n) => n <= 0 ? 1 : fib(n-1) + fib(n-2);
console.log(fib(10));
```

You can run it like follows:
```bash
#!/bin/bash
# main.sh

node fib.js
```