Refactored root screen

app/scenes/RootScreen/index.js

@@ -1,30 +1,23 @@
-import React, { Component } from 'react';
 import { connect } from 'react-redux';
 import { PropTypes } from 'prop-types';
-import NavigationService from '@services/NavigationService';
 import AppNavigator from '@navigators/AppNavigator';
 import Container from '@atoms/Container';
-
+import React, { useEffect } from 'react';
+import { setRefForTopLevelNavigtor } from '@app/services/NavigationService';
 import { rootScreenActions } from './reducer';
 
-export class RootScreen extends Component {
-  componentDidMount() {
-    // Run the startup saga when the application is starting
-    this.props.startup();
-  }
-
-  setRefForTopLevelNavigtor = navigatorRef => {
-    NavigationService.setTopLevelNavigator(navigatorRef);
-  };
+const RootScreen = props => {
+  useEffect(() => {
+    // Run the startup function when the component mounts
+    props.startup();
+  }, []);
 
-  render() {
-    return (
-      <Container testID="root-screen">
-        <AppNavigator />
-      </Container>
-    );
-  }
-}
+  return (
+    <Container testID="root-screen">
+      <AppNavigator ref={setRefForTopLevelNavigtor} />
+    </Container>
+  );
+};
 
 RootScreen.propTypes = {
   startup: PropTypes.func
@@ -33,5 +26,5 @@
 const mapDispatchToProps = dispatch => ({
   startup: () => dispatch(rootScreenActions.startup())
 });
-
 export default connect(null, mapDispatchToProps)(RootScreen);
+export { RootScreen as RootScreenTest };

app/scenes/RootScreen/saga.js

@@ -1,12 +1,12 @@
 import { takeLatest } from 'redux-saga/effects';
-import NavigationService from '@app/services/NavigationService';
+import { navigateAndReset } from '@app/services/NavigationService';
 import { rootScreenTypes } from './reducer';
 
 /**
  * The startup saga is the place to define behavior to execute when the application starts.
  */
 export function* startup() {
-  setTimeout(() => NavigationService.navigateAndReset('MainScreen'), 1000);
+  setTimeout(() => navigateAndReset('MainScreen'), 1000);
 }
 
 export default function* startUpSaga() {

app/scenes/RootScreen/tests/index.test.js

@@ -6,26 +6,23 @@
 
 import React from 'react';
 import { renderWithIntl } from 'app/utils/testUtils';
-import { RootScreen as RootScreenTest } from '../index';
-
+import { RootScreenTest } from '../index';
+export const setupJest = () => ({ submitSpy: jest.fn() });
 describe('<HomeScreen /> container', () => {
-  let submitSpy;
-
-  beforeAll(() => {
-    submitSpy = jest.fn();
-  });
-
   it('should render and match the snapshot', () => {
+    const { submitSpy } = setupJest();
     const baseElement = renderWithIntl(<RootScreenTest startup={submitSpy} />);
     expect(baseElement).toMatchSnapshot();
   });
 
   it('should call the startup prop on mount', () => {
+    const { submitSpy } = setupJest();
     renderWithIntl(<RootScreenTest startup={submitSpy} />);
     expect(submitSpy).toHaveBeenCalled();
   });
 
   it('should not render rootSceen Container', () => {
+    const { submitSpy } = setupJest();
     const { getByTestId } = renderWithIntl(
       <RootScreenTest startup={submitSpy} />
     );

app/scenes/RootScreen/tests/reducer.test.js

@@ -6,21 +6,30 @@ import {
 
 /* eslint-disable default-case, no-param-reassign */
 describe('Tests for RootScreen reducers', () => {
-  let state;
-  beforeEach(() => {
-    state = initialState;
-  });
+  const setupTests = () => ({ state: initialState });
 
   it('should return the initial state', () => {
+    const { state } = setupTests();
     expect(rootContainerReducer(undefined, {})).toEqual(state);
   });
 
   it('should return the initial state when an action of type STARTUP is dispatched', () => {
+    const { state } = setupTests();
     // since startup is called to initiate screen navigation the store should remain intact
     expect(
       rootContainerReducer(state, {
         type: rootScreenTypes.STARTUP
       })
     ).toEqual(state);
   });
+
+  it('should return the initial state when an action of type NONEXIST is dispatched', () => {
+    const { state } = setupTests();
+    // since startup is called to initiate screen navigation the store should remain intact
+    expect(
+      rootContainerReducer(state, {
+        type: rootScreenTypes.NONEXIST
+      })
+    ).toEqual(state);
+  });
 });