[EC-598] fix: user interaction not being awaited sometimes

Only one handler can return a response. That handler needs to return true to indicated it's intention to eventually do so.
Our issue was that multiple handlers were returning truthy values, causing a race condition.

apps/browser/src/background/runtime.background.ts

@@ -42,18 +42,27 @@ export default class RuntimeBackground {
     }
 
     await this.checkOnInstalled();
-    const backgroundMessageListener = async (
+    const backgroundMessageListener = (
       msg: any,
       sender: chrome.runtime.MessageSender,
       sendResponse: any
     ) => {
-      const response = await this.processMessage(msg, sender);
+      const messagesWithResponse = ["fido2RegisterCredentialRequest", "fido2GetCredentialRequest"];
-      sendResponse(response);
+
+      if (messagesWithResponse.includes(msg.command)) {
+        this.processMessage(msg, sender).then(
+          (value) => sendResponse({ result: value }),
+          (error) => sendResponse({ error: { ...error, message: error.message } })
+        );
+        return true;
+      }
+
+      this.processMessage(msg, sender);
+      return false;
     };
 
     BrowserApi.messageListener("runtime.background", (msg, sender, sendResponse) => {
-      backgroundMessageListener(msg, sender, sendResponse);
+      return backgroundMessageListener(msg, sender, sendResponse);
-      return true;
     });
     if (this.main.popupOnlyContext) {
       (window as any).bitwardenBackgroundMessageListener = backgroundMessageListener;
@@ -209,17 +218,9 @@ export default class RuntimeBackground {
         this.platformUtilsService.copyToClipboard(msg.identifier, { window: window });
         break;
       case "fido2RegisterCredentialRequest":
-        try {
+        return await this.main.fido2Service.createCredential(msg.data);
-          return { result: await this.main.fido2Service.createCredential(msg.data) };
-        } catch (error) {
-          return { error: { ...error, message: error.message } };
-        }
       case "fido2GetCredentialRequest":
-        try {
+        return await this.main.fido2Service.assertCredential(msg.data);
-          return { result: await this.main.fido2Service.assertCredential(msg.data) };
-        } catch (error) {
-          return { error: { ...error, message: error.message } };
-        }
     }
     return undefined;
   }

apps/browser/src/browser/browserApi.ts

@@ -139,8 +139,8 @@ export class BrowserApi {
     callback: (message: any, sender: chrome.runtime.MessageSender, response: any) => unknown
   ) {
     chrome.runtime.onMessage.addListener(
-      (msg: any, sender: chrome.runtime.MessageSender, response: any) => {
+      (msg: any, sender: chrome.runtime.MessageSender, sendResponse: any) => {
-        return callback(msg, sender, response);
+        return callback(msg, sender, sendResponse) === true;
       }
     );
   }