Convert javascript class instance to plain object preserving methods

Lots of answers already, but this is the simplest yet by using the spread syntax and de-structuring the object:

const {...object} = classInstance

This is what's working for me

const classToObject = theClass => {
  const originalClass = theClass || {}
  const keys = Object.getOwnPropertyNames(Object.getPrototypeOf(originalClass))
  return keys.reduce((classAsObj, key) => {
    classAsObj[key] = originalClass[key]
    return classAsObj
  }, {})
}