working on tests for the improved config.json handling (ref. #48)

__tests__/service-worker/service-worker.test.js

@@ -111,7 +111,7 @@ beforeAll(async ()=>{
      */
     window.registration = {
         scope: "https://test.resilient.is/",
-        unregister: ()=>{}
+        unregister: spy(()=>{})
     }
     
     /*
@@ -370,6 +370,20 @@ describe('service-worker', async () => {
         assertSpyCalls(self.fetch, 1)
     })
     
+    it("should throw a meaningful exception when an unhandled exception occurs during initialization", async () => {
+        
+        // this will generate an exception on line where a new Map()
+        // is created from self.LibResilientPluginConstructors
+        self.LibResilientPluginConstructors = true
+        
+        await import("../../service-worker.js?" + window.test_id);
+        
+        // the a failed install event handler in the service worker code
+        // will run self.registration.unregister() to not leave the site in a broken state
+        await self.dispatchEvent(new Event('install'))
+        assertSpyCalls(self.registration.unregister, 1)
+    })
+    
     it("should use default LibResilientConfig values when fetching config.json throws an exception", async () => {
         
         window.fetch = spy(() => {

service-worker.js

@@ -641,7 +641,7 @@ let initServiceWorker = async () => {
         // we got an error while initializing the service worker!
         // better play it safe!
         self.registration.unregister()
-        throw e
+        return false
     }
     return true;
 }
@@ -1131,11 +1131,12 @@ let getResourceThroughLibResilient = (url, init, clientId, useStashed=true, doSt
 |* === Setting up the event handlers                                     === *|
 \* ========================================================================= */
 self.addEventListener('install', async (event) => {
-    await event.waitUntil(
-        initServiceWorker()
-    )
-    // "COMMIT_UNKNOWN" will be replaced with commit ID
-    self.log('service-worker', "0. Installed LibResilient Service Worker (commit: COMMIT_UNKNOWN).");
+    let init_promise = initServiceWorker()
+    await event.waitUntil(init_promise)
+    if (await init_promise === true) {
+        // "COMMIT_UNKNOWN" will be replaced with commit ID
+        self.log('service-worker', "0. Installed LibResilient Service Worker (commit: COMMIT_UNKNOWN).");
+    }
 });
 
 self.addEventListener('activate', async event => {