added testing, modified components wit data-testid

Author: minzo-kim

src/app/__tests__zo/Dropdown.test.tsx

@@ -5,12 +5,6 @@ import '@testing-library/jest-dom/extend-expect'; // needed this to extend the j
 
 import Dropdown from '../components/Dropdown';
 
-// interface DropdownProps {
-//   selectedSpeed: { value: number; label: string };
-//   speeds: { value: number; label: string }[];
-//   setSpeed: () => void;
-// }
-
 describe('Dropdown test', () => {
   const speeds = [
     { value: 1, label: 'test1' },

src/app/__tests__zo/TravelContainer.test.tsx

@@ -24,7 +24,6 @@ const state = {
 
 // mock play?
 const play = jest.fn(() => console.log('legit'));
-// play.mockImplementation(() => console.log('legit'));
 
 const dispatch = jest.fn();
 useStoreContext.mockImplementation(() => [state, dispatch]);

src/app/containers/TravelContainer.tsx

@@ -62,6 +62,7 @@ function TravelContainer(props: TravelContainerProps): JSX.Element {
       <button
         className='play-button'
         type='button'
+        // data-testid, prop for testing in RTL
         data-testid='play-button-test'
         onClick={() => play(selectedSpeed.value, playing, dispatch, snapshotsLength, sliderIndex)}
       >