Add share target (#469)

* Quick test

* More testing

* More testing

* Removing transfer for now

* Changing name so it's easier to tell them apart when installed

* Disable minification to ease debugging

* Adding navigate lock

* lol oops

* Add minifying back

* Removing minification again, for debugging

* Removing broadcast channel bits, to simplify the code

* Revert "Removing broadcast channel bits, to simplify the code"

This reverts commit 0b2a3ecf2986aae0dd65fdd1ddda2bd9e4e1eac7.

* I think this fixes it

* Refactor

* Suppress flash of home screen during share target

* Almost ready, so switching to real name

* Removing log

* Ahh yes the trailing comma thing

* Removing use of BroadcastChannel

* Reducing ternary

src/sw/index.ts

@@ -1,5 +1,6 @@
 import {
   cacheOrNetworkAndCache, cleanupCache, cacheOrNetwork, cacheBasics, cacheAdditionalProcessors,
+  serveShareTarget,
 } from './util';
 import { get } from 'idb-keyval';
 
@@ -40,14 +41,23 @@ self.addEventListener('activate', (event) => {
 });
 
 self.addEventListener('fetch', (event) => {
-  // We only care about GET.
-  if (event.request.method !== 'GET') return;
-
   const url = new URL(event.request.url);
 
   // Don't care about other-origin URLs
   if (url.origin !== location.origin) return;
 
+  if (
+    url.pathname === '/' &&
+    url.searchParams.has('share-target') &&
+    event.request.method === 'POST'
+  ) {
+    serveShareTarget(event);
+    return;
+  }
+
+  // We only care about GET from here on in.
+  if (event.request.method !== 'GET') return;
+
   if (url.pathname.startsWith('/demo-') || url.pathname.startsWith('/wc-polyfill')) {
     cacheOrNetworkAndCache(event, dynamicCache);
     cleanupCache(event, dynamicCache, BUILD_ASSETS);