index.js
function rayLineVsCircle(ray, circle) {
  var rayLine = new Line2(
    ray.start.x,
    ray.start.y,
    ray.end.x,
    ray.end.y
  );

  return rayLine.intersectCircle(circle.position, circle.radius);
}
function rayLineVsCircle(ray, circle) {
  var rayLine = new Line2(
    ray.start.x,
    ray.start.y,
    ray.end.x,
    ray.end.y
  );

  return rayLine.intersectCircle(circle.position, circle.radius);
}
Treats ray like an infinite line see where it intersects circle.

@param {object} ray - ray-like
@param {Circle2} circle
@return {Array} containing 0, 1, or 2 Vec2 where line hits circle