You can add this code in the App.test.js. It is not necessary to create another test file.

jest-division-test.js

test('performs division', () => {
  render(<App />);

  const inputElement = screen.getByRole('textbox');
   // Check the value of the textbox (initially it should be an empty string)
  expect(inputElement.value).toBe('');

  // Simulate clicking the buttons to enter the expression "2+3" into the calculator
  fireEvent.click(screen.getByText('1'));
  expect( inputElement.value ).toBe("1")

  fireEvent.click(screen.getByText('0'));
  expect( inputElement.value ).toBe("10")
  // expect(inputElement.textContent).toBe(' 2');

  fireEvent.click(screen.getByText('/'));
  expect(inputElement.value).toBe('10/');

  fireEvent.click(screen.getByText('2'));
  expect(inputElement.value).toBe('10/2');


  // Simulate clicking the "=" button
  fireEvent.click(screen.getByText('='));

  //select the 'result' div and check if it's value is 5
  const resultElement = screen.getByTestId('result');
  expect(resultElement.textContent).toBe('5');//or expect(resultElement).toHaveTextContent('5')
});