Function isError

isError<T extends BridgeResponse>(
response: T,
): response is Extract<T, { error: string }>
Type guard to check if a JSBridge response is an error (4xx or 5xx status codes).
Type Parameters
- T extends BridgeResponse
Parameters
- response: T
  The JSBridge response to check
Returns response is Extract<T, { error: string }>
True if the response is any error (4xx or 5xx), false otherwise
Example
```
const response = await someBridgeMethod();
if (isError(response)) {
  // response narrowed to error variants — error: string is guaranteed
  console.error('Error:', response.error);
} else {
  console.log('Success!');
}
```