webpack.prod.conf.js

var SWPrecacheWebpackPlugin = require('sw-precache-webpack-plugin')

...

var webpackConfig = merge(baseWebpackConfig, {
  ...
  plugins: [
    ...
    // service worker caching
    new SWPrecacheWebpackPlugin({
      cacheId: 'my-vue-app',
      filename: 'service-worker.js',
      staticFileGlobs: ['dist/**/*.{js,html,css}'],
      minify: true,
      stripPrefix: 'dist/',
      runtimeCaching: [
      {
        urlPattern: /^https:\/\/fonts\.googleapis\.com\//,
        handler: 'cacheFirst'
      },
      {
        urlPattern: /^https:\/\/fonts\.gstatic\.com\//,
        handler: 'cacheFirst'
      },
      {
        urlPattern: /^https:\/\/code\.getmdl\.io\//,
        handler: 'cacheFirst'
      }]
    })
  ]
})