Fix error boxes from server-side silenced errors

Author: GrantGryczan

frontend/composables/useErrorBoxes.ts

@@ -21,6 +21,12 @@ export default function useErrorBoxes() {
     },
 
     handleError(error: unknown) {
+      // Client-side listeners stop silenced errors from getting this far, but
+      // unfortunately there's currently nothing to stop them server-side.
+      if (import.meta.server && isSilenced(error)) {
+        return;
+      }
+
       if (error instanceof FetchError && error.response) {
         errorBoxes.open({
           message: error.response.status + " " + error.response.statusText,

frontend/utils/silence.ts

@@ -9,7 +9,7 @@ export default function silence<T extends WeakKey>(error: T): T {
 }
 
 /** Checks if {@link silence} was ever called on an error. */
-function isSilenced(error: unknown): boolean {
+export function isSilenced(error: unknown): boolean {
   // @ts-expect-error `WeakSet.prototype.has` already returns `false` for
   // incorrect types, which is the desired behavior.
   return silencedErrors.has(error);