public string ValidateMatchingAuthors(IEnumerable <Author> authors, ICollection <AuthorDto> authorDtos)
{
if (authors.Count() != authorDtos.Count())
{
var ids = string.Join(", ", authorDtos.Select(a => a.Id));
var names = string.Join(", ", authorDtos.Select(a => a.Name));
return(authorDtos != null?ValidationErrorMessages.AuthorNotFound(ids, names) : string.Empty);
}
return(string.Empty);
}
public string ValidateAuthorWasFound(string name, Author author)
{
return((author == null) ? ValidationErrorMessages.AuthorNotFound(name) : string.Empty);
}