fix: allow useRiveFile to work with undefined input

Author: mfazekas

src/hooks/useRiveFile.ts

@@ -70,10 +70,11 @@ function transformFilesHandledMapping(
 type RiveFileHookResult =
   | { riveFile: RiveFile; isLoading: false; error: null }
   | { riveFile: null; isLoading: true; error: null }
-  | { riveFile: null; isLoading: false; error: string };
+  | { riveFile: null; isLoading: false; error: string }
+  | { riveFile: null; isLoading: false; error: null };
 
 export function useRiveFile(
-  input: RiveFileInput,
+  input: RiveFileInput | undefined,
   options: UseRiveFileOptions = {}
 ): RiveFileHookResult {
   const [result, setResult] = useState<RiveFileHookResult>({
@@ -122,7 +123,15 @@ export function useRiveFile(
           );
         }
 
-        setResult({ riveFile: currentFile!, isLoading: false, error: null });
+        if (currentFile == null) {
+          setResult({
+            riveFile: null,
+            isLoading: false,
+            error: 'Failed to load Rive file: Input not provided.',
+          });
+        } else {
+          setResult({ riveFile: currentFile!, isLoading: false, error: null });
+        }
       } catch (err) {
         console.error(err);
         setResult({