Handle errors during "fetch" action (#44)

src/background.js

@@ -333,12 +333,21 @@ async function handleMessage(settings, message, sendResponse) {
     // check that action is present
     if (typeof message !== "object" || !message.hasOwnProperty("action")) {
         sendResponse({ status: "error", message: "Action is missing" });
+        return;
     }
 
     // fetch file & parse fields if a login entry is present
+    try {
         if (typeof message.login !== "undefined") {
             await parseFields(settings, message.login);
         }
+    } catch (e) {
+        sendResponse({
+            status: "error",
+            message: "Unable to fetch and parse login fields: " + e.toString()
+        });
+        return;
+    }
 
     // route action
     switch (message.action) {