almost working except for a bug on add.html

app/service-worker.js

@@ -5,6 +5,7 @@ const ASSETS = `cache${timestamp}`
 // `shell` is an array of all the files generated by webpack,
 // `assets` is an array of everything in the `assets` directory
 const toCache = shell.concat(assets)
+  .concat(['/'])
   .filter(filename => !filename.endsWith('.map'))
   .filter(filename => !filename.startsWith('apple-icon'))
 const cached = new Set(toCache)
@@ -58,7 +59,7 @@ self.addEventListener('fetch', event => {
 
     if (url.origin === self.origin &&
         routes.find(route => route.pattern.test(url.pathname))) {
-      return caches.match('/index.html')
+      return caches.match('/')
     }
 
     // For these GET requests, go cache-first

package-lock.json

@@ -7960,7 +7960,7 @@
       }
     },
     "sapper": {
-      "version": "github:nolanlawson/sapper#f8410836609759a6435db16512b1f9ecf7b091b2",
+      "version": "github:nolanlawson/sapper#2f8b7b646ace50fbb2f18b7b989f66d08b6c690a",
       "requires": {
         "cheerio": "1.0.0-rc.2",
         "chokidar": "2.0.2",

package.json

@@ -53,7 +53,7 @@
     "pify": "^3.0.0",
     "quick-lru": "^1.1.0",
     "requestidlecallback": "^0.3.0",
-    "sapper": "nolanlawson/sapper#ignore-source-maps-built",
+    "sapper": "github:nolanlawson/sapper#ignore-source-maps-built",
     "serve-static": "^1.13.1",
     "standard": "^10.0.3",
     "stringz": "^0.4.0",

webpack/service-worker.config.js

@@ -1,7 +1,11 @@
 const config = require('sapper/webpack/config.js')
 
+const mode = process.env.NODE_ENV
+const isDev = mode === 'development'
+
 module.exports = {
   entry: config.serviceworker.entry(),
   output: config.serviceworker.output(),
-  mode: process.env.NODE_ENV
+  mode: process.env.NODE_ENV,
+  devtool: isDev ? 'inline-source-map' : 'source-map'
 }