Rotating Toward an Object at a Constant Speed

I am trying to make an object rotate toward another object's position at a constant speed. Kind of like LookAt, except LookAt always looks directly at the object at infinite speed. In mine, the object can only rotate at a certain speed. Can you give me a script in js? Thanks.

This will turn toward a target position at a constant speed, which is determined by the "damping" variable.

function Update()
{

// Look at and dampen the rotation

    var rotation = Quaternion.LookRotation(target.position - transform.position);
    transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * damping);
    }

You could use Mathf.SmoothDamp or Mathf.Lerp.

Or take a look at this answer: smooth LookAt()