I have the following js file:

function createButtons(input) {
 // implementation
}

function createMessage({buttonInput}) {
  const message = {};

  if(buttonInput) {
    message.buttons = createButtons(buttonInput)
  }

  return message;
}


module.exports = {
  createButtons,
  createMessage
}

How can I create a mock of createButtons to return a known value when I’m making a test for createMessage?

I attempted create a mock by importing createButtons and passing it to jest.spyOn, but that doesn’t seem to work.

const spy = jest.spyOn(createButtons).mockImplementationOnce(() => true);

Is there a better way to write or test this?