Text styles in the flutter

text_styles.dart

extension TextExtension on TextStyle {
  TextStyle white([double opacity = 1.0]) => copyWith(
        color: ColorName.white.withOpacity(opacity),
      );

  // ANOTHER TEXT COLORS ...

  TextStyle customColor(Color color, [double opacity = 1.0]) => copyWith(
        color: color.withOpacity(opacity),
      );
}

class TextStyles {
  TextStyles._();

  static const double _lineSpacing = 1.65;

  static const double _textSizeVerySmall = 12.0;
  static const double _textSizeSmall = 14.0;
  // ANOTHER TEXT SIZE ...

  static const TextStyle defaultStyle = TextStyle(
    height: _lineSpacing,
    color: ColorName.black,
  );

  //VERY SMALL
  static TextStyle verySmall = defaultStyle.copyWith(
    fontSize: _textSizeVerySmall,
    fontFamily: defaultRegularFontName,
  );

  static TextStyle verySmallBold = verySmall.copyWith(
    fontFamily: defaultBoldFontName,
  );

  //SMALL
  static TextStyle small = defaultStyle.copyWith(
    fontSize: _textSizeSmall,
    fontFamily: defaultRegularFontName,
  );

  static TextStyle smallBold = small.copyWith(
    fontFamily: defaultBoldFontName,
  );

  // ANOTHER TEXT STYLES ...
}