assume error response might or might not wrapped in an array

Author: milaGGL

packages/firestore/src/platform/browser/webchannel_connection.ts

@@ -97,11 +97,11 @@ export class WebChannelConnection extends RestConnection {
                 xhr.getResponseText()
               );
               if (status > 0) {
-                let response = xhr.getResponseJson() as WebChannelError;
+                let response = xhr.getResponseJson();
                 if (Array.isArray(response)) {
                   response = response[0];
                 }
-                const responseError = response?.error;
+                const responseError = (response as WebChannelError)?.error;
                 if (
                   !!responseError &&
                   !!responseError.status &&

packages/firestore/src/platform/browser_lite/fetch_connection.ts

@@ -69,18 +69,11 @@ export class FetchConnection extends RestConnection {
     }
 
     if (!response.ok) {
-      let errorResponse;
-      try {
-        [errorResponse] = (await response.json()) as [
-          {
-            error?: { message?: string };
-          }
-        ];
-      } catch (_ignored) {}
-      let errorMessage;
-      if (errorResponse) {
-        errorMessage = errorResponse.error?.message;
+      let errorResponse = await response.json();
+      if (Array.isArray(errorResponse)) {
+        errorResponse = errorResponse[0];
       }
+      const errorMessage = errorResponse?.error?.message;
       throw new FirestoreError(
         mapCodeFromHttpStatus(response.status),
         `Request failed with error: ${errorMessage ?? response.statusText}`