push-permissions.js

import { Permissions } from "expo";

async function registerForPushNotificationsAsync() {
  const { status: existingStatus } = await Permissions.getAsync(
    Permissions.NOTIFICATIONS
  );
  let finalStatus = existingStatus;

  // only ask if permissions have not already been determined, because
  // iOS won't necessarily prompt the user a second time.
  if (existingStatus !== "granted") {
    // Android remote notification permissions are granted during the app
    // install, so this will only ask on iOS
    const { status } = await Permissions.askAsync(Permissions.NOTIFICATIONS);
    finalStatus = status;
  }

  // Stop here if the user did not grant permissions
  if (finalStatus !== "granted") {
    return;
  }
}