resolveValue method

Implementation

// Value resolution

/// Returns the resolved value of this configuration option from the provided context.
/// For options with positional arguments this must be invoked in ascending position order.
/// Returns the result with the resolved value or error.
///
/// This method is intended for internal use.
OptionResolution<V> resolveValue(
  final Configuration cfg, {
  final ArgResults? args,
  final Iterator<String>? posArgs,
  final Map<String, String>? env,
  final ConfigurationBroker? configBroker,
}) {
  OptionResolution<V> res;
  try {
    res = _doResolve(
      cfg,
      args: args,
      posArgs: posArgs,
      env: env,
      configBroker: configBroker,
    );
  } on Exception catch (e) {
    return OptionResolution.error(
      'Failed to resolve ${option.qualifiedString()}: $e',
    );
  }

  if (res.error != null) {
    return res;
  }

  final stringValue = res.stringValue;
  if (stringValue != null) {
    // value provided by string-based config source, parse to the designated type
    try {
      res = res.copyWithValue(
        option.option.valueParser.parse(stringValue),
      );
    } on FormatException catch (e) {
      return res.copyWithError(
        _makeFormatErrorMessage(e),
      );
    }
  }

  final error = validateOptionValue(res.value);
  if (error != null) return res.copyWithError(error);

  return res;
}