/// <summary>
/// Update KeyValue only if specific key already exist.
/// Return error message if not.
/// </summary>
private CommandResult Update(string key, string value)
{
try
{
if (key is null || key.Trim().Length == 0)
{
throw new ArgumentNullException("key");
}
if (value is null)
{
throw new ArgumentNullException("value");
}
_store.UpdateValue(key, value);
}
catch (KeyNotFoundInRepositoryException)
{
return(new FailureResult
{
ErrorMessage = "key not found"
});
}
catch (ArgumentNullException e)
{
return(new FailureResult
{
ErrorMessage = e.ParamName + " is required"
});
}
return(new SuccessResult());
}