props-getter.js

const logClick = () => console.log("button clicked");

const callAll = (...fns) => (...args) => fns.forEach((fn) => fn(...args));

export const buttonPropsGetter = ({ customOnClick, ...props }) => ({
  onClick: callAll(logClick, customOnClick), // Extensible
  tabIndex: 0,
  role: "button",
  "aria-disabled": false,
  text: "Button",
  ...props // The overrides
});

const Button = ({ text, buttonProps }) => {
  return <button {...buttonProps}>{text}</button>;
};

// Usage:
<Button
  {...buttonPropsGetter({
    customOnClick: () => console.log("Sent email"),
    text: "Send"
  })}
/>