How to export a functional component function?

Question

Given the following functional component, how do I export someFunction without breaking it out into a separate file , so that I may test it?

const MyComponent = () => {

  const someFunction = () => {
    ...
    return someValue;
  };

  const [value, setValue] = useState(0);

  useEffect(() => {
    setValue(someFunction());
  }, []);

  return (
    <div>
      ...
    </div>
  );
};

Adding an export in front of the function declaration does not seem to work.

Answer 1

Like @yury-tarabanko mentioned the export keyword can only be used in the module scope, aka the file root.

export const someFunction = () => {
  ...
  return someValue;
};

export const MyComponent = () => {

  const [value, setValue] = useState(0);

  useEffect(() => {
    setValue(someFunction());
  }, []);

  return (
    <div>
      ...
    </div>
  );
};

Answer 2

Just do export default function FunctionName(){ }

or

const MyComponent = () => {

  const someFunction = () => {
    ...
    return someValue;
  };

  const [value, setValue] = useState(0);

  useEffect(() => {
    setValue(someFunction());
  }, []);

  return (
    <div>
      ...
    </div>
  );
};

export default Mycomponent