feat: add test for catching errors in Emitter

test/serviceWorker.test.ts

@@ -0,0 +1,9 @@
+describe("serviceWorker", () => {
+  it("should add the proper eventListeners", () => {
+    // make sure install, active and fetch were added as event listeners
+  })
+
+  it("should call the proper callbacks", () => {
+    // somehow test Line 8 with the events waitUntil..
+  })
+})