resources.js

const fs = require('fs');

function copyImages(sourcePath, targetPath, images) {
  for (const icon of images) {
    let source = sourcePath + icon.source;
    let target = targetPath + icon.target;
    fs.copyFile(source, target, err => {
      if (err) throw err;
      console.log(`${source} >> ${target}`);
    });
  }
}

const SOURCE_ANDROID_ICON = 'resources/android/icon/';
const SOURCE_ANDROID_SPLASH = 'resources/android/splash/';

const TARGET_ANDROID_ICON = 'android/app/src/main/res/';
const TARGET_ANDROID_SPLASH = 'android/app/src/main/res/';

const ANDROID_ICONS = [
  { source: 'drawable-ldpi-icon.png', target: 'drawable-hdpi-icon.png' },
  { source: 'drawable-mdpi-icon.png', target: 'mipmap-mdpi/ic_launcher.png' },
  { source: 'drawable-mdpi-icon.png', target: 'mipmap-mdpi/ic_launcher_round.png' },
  { source: 'drawable-mdpi-icon.png', target: 'mipmap-mdpi/ic_launcher_foreground.png' },
  { source: 'drawable-hdpi-icon.png', target: 'mipmap-hdpi/ic_launcher.png' },
  { source: 'drawable-hdpi-icon.png', target: 'mipmap-hdpi/ic_launcher_round.png' },
  { source: 'drawable-hdpi-icon.png', target: 'mipmap-hdpi/ic_launcher_foreground.png' },
  { source: 'drawable-xhdpi-icon.png', target: 'mipmap-xhdpi/ic_launcher.png' },
  { source: 'drawable-xhdpi-icon.png', target: 'mipmap-xhdpi/ic_launcher_round.png' },
  { source: 'drawable-xhdpi-icon.png', target: 'mipmap-xhdpi/ic_launcher_foreground.png' },
  { source: 'drawable-xxhdpi-icon.png', target: 'mipmap-xxhdpi/ic_launcher.png' },
  { source: 'drawable-xxhdpi-icon.png', target: 'mipmap-xxhdpi/ic_launcher_round.png' },
  { source: 'drawable-xxhdpi-icon.png', target: 'mipmap-xxhdpi/ic_launcher_foreground.png' },
  { source: 'drawable-xxxhdpi-icon.png', target: 'mipmap-xxxhdpi/ic_launcher.png' },
  { source: 'drawable-xxxhdpi-icon.png', target: 'mipmap-xxxhdpi/ic_launcher_round.png' },
  { source: 'drawable-xxxhdpi-icon.png', target: 'mipmap-xxxhdpi/ic_launcher_foreground.png' }
];
const ANDROID_SPLASHES = [
  { source: 'drawable-land-mdpi-screen.png', target: 'drawable/splash.png' }, 
  { source: 'drawable-land-mdpi-screen.png', target: 'drawable-land-mdpi/splash.png' },
  { source: 'drawable-land-hdpi-screen.png', target: 'drawable-land-hdpi/splash.png' },
  { source: 'drawable-land-xhdpi-screen.png', target: 'drawable-land-xhdpi/splash.png' },
  { source: 'drawable-land-xxhdpi-screen.png', target: 'drawable-land-xxhdpi/splash.png' },
  { source: 'drawable-land-xxxhdpi-screen.png', target: 'drawable-land-xxxhdpi/splash.png' },
  { source: 'drawable-port-mdpi-screen.png', target: 'drawable-port-mdpi/splash.png' },
  { source: 'drawable-port-hdpi-screen.png', target: 'drawable-port-hdpi/splash.png' },
  { source: 'drawable-port-xhdpi-screen.png', target: 'drawable-port-xhdpi/splash.png' },
  { source: 'drawable-port-xxhdpi-screen.png', target: 'drawable-port-xxhdpi/splash.png' },
  { source: 'drawable-port-xxxhdpi-screen.png', target: 'drawable-port-xxxhdpi/splash.png' }
];

copyImages(SOURCE_ANDROID_ICON, TARGET_ANDROID_ICON, ANDROID_ICONS);
copyImages(SOURCE_ANDROID_SPLASH, TARGET_ANDROID_SPLASH, ANDROID_SPLASHES);