Function requiredFileValidator

requiredFileValidator(
isRequired?: boolean,
errorMessage?: string,
): SyncValidationFunction<File | null>
Returns a validation function to validate that a file is not null if the value is required.
Parameters
- OptionalisRequired: boolean
  Indicates if the value is required.
- OptionalerrorMessage: string
  A custom error message to display if the value is invalid.
Returns SyncValidationFunction<File | null>