Deep copy/clone a class instance in Javascript

index.js

/**
 * @function
 * @description Deep clone a class instance.
 * @param {object} instance The class instance you want to clone.
 * @returns {object} A new cloned instance.
 */
function clone(instance) {
  return Object.assign(
    Object.create(
      // Set the prototype of the new object to the prototype of the instance.
      // Used to allow new object behave like class instance.
      Object.getPrototypeOf(instance),
    ),
    // Prevent shallow copies of nested structures like arrays, etc
    JSON.parse(JSON.stringify(instance)),
  );
}

Thanks for this! I've considered a few options and this seems to be the best way to copy a JavaScript class instance.

"Uncaught TypeError: clone is not a constructor" - how to deal with it?

@Xsaven it's a function not a class.

Be Sure to Import the Method

then call it like that:

clone(yourInstance)

optional (but my preference):

you can put this function into a class and call it then as function from the instance you've got alrdy (But you have to adjust the syntax to class functions), like

const clonedClass = yourClass.clone(yourInstance)

^ for example ^

thank you, random github people. this saved my day

I get this error :
Uncaught TypeError: Converting circular structure to JSON --> starting at object with constructor 'Object' | property 'links' -> object with constructor 'Object' | index 0 -> object with constructor 'Object' --- property 'to' closes the circle