navigation.js

import React from 'react'
import { createStackNavigator } from '@react-navigation/stack'
import { NavigationContainer } from '@react-navigation/native'
import HomeScreen from './screens/HomeScreen'
import NewPostScreen from './screens/NewPostScreen'
import LoginScreen from './screens/LoginScreen'
import SignupScreen from './screens/SignupScreen'

const Stack = createStackNavigator()

const screenOptions = {
    headerShown: false,
}

export const SignedInstack = () => (
    <NavigationContainer>
        <Stack.Navigator initialRouteName='HomeScreen' screenOptions={screenOptions}>
            <Stack.Screen name='HomeScreen' component={HomeScreen}/>
            <Stack.Screen name='NewPostScreen' component={NewPostScreen}/>
        </Stack.Navigator>
    </NavigationContainer>
)

export const SignedOutStack = () => (
    <NavigationContainer>
        <Stack.Navigator initialRouteName='LoginScreen' screenOptions={screenOptions}>
            <Stack.Screen name='LoginScreen' component={LoginScreen}/>
            <Stack.Screen name='SignupScreen' component={SignupScreen}/>
        </Stack.Navigator>
    </NavigationContainer>
)