App.js

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 *
 * @format
 * @flow strict-local
 */

import React from 'react';
import {
  SafeAreaView,
  StyleSheet,
  ScrollView,
  View,
  Text,
  StatusBar,
  Button,
  Alert
} from 'react-native';

import {
  Header,
  LearnMoreLinks,
  Colors,
  DebugInstructions,
  ReloadInstructions,
} from 'react-native/Libraries/NewAppScreen';

import { HmsPushInstanceId } from "@hmscore/react-native-hms-push";
import HMSAvailability, { ErrorCode } from '@hmscore/react-native-hms-availability';

const App: () => React$Node = () => {
  return (
    <>
      <StatusBar barStyle="dark-content" />
      <SafeAreaView>
        <ScrollView
          contentInsetAdjustmentBehavior="automatic"
          style={styles.scrollView}>
          <Header />
          {global.HermesInternal == null ? null : (
            <View style={styles.engine}>
              <Text style={styles.footer}>Engine: Hermes</Text>
            </View>
          )}
          <Button
            onPress={() => checkHMS()}
            title="Check HMS status"
          />
          <View style={styles.body}>
            <View style={styles.sectionContainer}>
              <Text style={styles.sectionTitle}>Step One</Text>
              <Text style={styles.sectionDescription}>
                Edit <Text style={styles.highlight}>App.js</Text> to change this
                screen and then come back to see your edits.
              </Text>
            </View>
            <View style={styles.sectionContainer}>
              <Text style={styles.sectionTitle}>See Your Changes</Text>
              <Text style={styles.sectionDescription}>
                <ReloadInstructions />
              </Text>
            </View>
            <View style={styles.sectionContainer}>
              <Text style={styles.sectionTitle}>Debug</Text>
              <Text style={styles.sectionDescription}>
                <DebugInstructions />
              </Text>
            </View>
            <View style={styles.sectionContainer}>
              <Text style={styles.sectionTitle}>Learn More</Text>
              <Text style={styles.sectionDescription}>
                Read the docs to discover what to do next:
              </Text>
            </View>
            <LearnMoreLinks />
          </View>
        </ScrollView>
      </SafeAreaView>
    </>
  );
};

const styles = StyleSheet.create({
  scrollView: {
    backgroundColor: Colors.lighter,
  },
  engine: {
    position: 'absolute',
    right: 0,
  },
  body: {
    backgroundColor: Colors.white,
  },
  sectionContainer: {
    marginTop: 32,
    paddingHorizontal: 24,
  },
  sectionTitle: {
    fontSize: 24,
    fontWeight: '600',
    color: Colors.black,
  },
  sectionDescription: {
    marginTop: 8,
    fontSize: 18,
    fontWeight: '400',
    color: Colors.dark,
  },
  highlight: {
    fontWeight: '700',
  },
  footer: {
    color: Colors.dark,
    fontSize: 12,
    fontWeight: '600',
    padding: 4,
    paddingRight: 12,
    textAlign: 'right',
  },
});

function checkHMS() {
  testHmsCorePresence()
    .then((hmsCoreOk) => testAccountByRequestingPushNotificationsToken())
    .then((pushTokenRetrieved) => Alert.alert("SUCCESS", "All good. Start hacking!"))
    .catch((anyError) => Alert.alert("FAIL", "" + anyError));
}

function testAccountByRequestingPushNotificationsToken() {
  return HmsPushInstanceId.getToken("")
    .then((pushTokenAsJsonObject) => {
      var pushToken;
      try {
        pushToken = pushTokenAsJsonObject.result;
      } catch (err) {
        return Promise.reject(new Error("Push notifications token retrieved but malformated."));
      }
      console.log("HMS Push token: " + pushToken);
      if (pushToken.isEmpty) {
        return Promise.reject(new Error("Push notifications token retrieved, but empty. Clear app data and try again."));
      } else {
        return Promise.resolve("PushToken:" + pushToken);
      }

    });
}

function testHmsCorePresence() {
  return HMSAvailability.isHuaweiMobileServicesAvailable().then((checkResult) => {
    if (checkResult == ErrorCode.HMS_CORE_APK_AVAILABLE) {
      return Promise.resolve("HMS Core available");
    } else {
      return HMSAvailability.getErrorString(checkResult)
        .then((errorExplained) => Promise.reject("HMS Core not available because: " + errorExplained));
    }
  });
}

export default App;