test: add basic unit tests for all navigators

packages/stack/src/__tests__/index.test.tsx

@@ -0,0 +1,33 @@
+import * as React from 'react';
+import { View, Text, Button } from 'react-native';
+import { render, fireEvent } from 'react-native-testing-library';
+import { NavigationContainer, ParamListBase } from '@react-navigation/native';
+import { createStackNavigator, StackScreenProps } from '../index';
+
+it('renders a stack navigator with screens', async () => {
+  const Test = ({ route, navigation }: StackScreenProps<ParamListBase>) => (
+    <View>
+      <Text>Screen {route.name}</Text>
+      <Button onPress={() => navigation.navigate('A')} title="Go to A" />
+      <Button onPress={() => navigation.navigate('B')} title="Go to B" />
+    </View>
+  );
+
+  const Stack = createStackNavigator();
+
+  const { findByText, queryByText } = render(
+    <NavigationContainer>
+      <Stack.Navigator>
+        <Stack.Screen name="A" component={Test} />
+        <Stack.Screen name="B" component={Test} />
+      </Stack.Navigator>
+    </NavigationContainer>
+  );
+
+  expect(queryByText('Screen A')).not.toBeNull();
+  expect(queryByText('Screen B')).toBeNull();
+
+  fireEvent.press(await findByText('Go to B'));
+
+  expect(queryByText('Screen B')).not.toBeNull();
+});