class UnderlineInputBorder extends InputBorder {
  /// Creates an underline border for an [InputDecorator].
  ///
  /// The [borderSide] parameter defaults to [BorderSide.none] (it must not be
  /// null). Applications typically do not specify a [borderSide] parameter
  /// because the input decorator substitutes its own, using [copyWith], based
  /// on the current theme and [InputDecorator.isFocused].
  ///
  /// The [borderRadius] parameter defaults to a value where the top left
  /// and right corners have a circular radius of 4.0. The [borderRadius]
  /// parameter must not be null.
  const UnderlineInputBorder({
    BorderSide borderSide = const BorderSide(),
    this.borderRadius = const BorderRadius.only(
      topLeft: Radius.circular(4.0),
      topRight: Radius.circular(4.0),
    ),
  }) : assert(borderRadius != null),
       super(borderSide: borderSide);

  @override
  bool operator ==(Object other) {
    if (identical(this, other))
      return true;
    if (other.runtimeType != runtimeType)
      return false;
    return other is InputBorder
        && other.borderSide == borderSide;
  }

  @override
  int get hashCode => borderSide.hashCode;
}

void main() {
  group('UnderlineInputBorder test', () {
    test('UnderlineInputBorder equality', () {
      // UnderlineInputBorder's equality is defined only by the borderSide
      const UnderlineInputBorder underlineInputBorder =
          UnderlineInputBorder(borderSide: BorderSide(color: Colors.blue));
      expect(
          underlineInputBorder,
          const UnderlineInputBorder(
              borderSide: BorderSide(color: Colors.blue)));
      expect(underlineInputBorder, isNot(const UnderlineInputBorder()));
      // UnderlineInputBorder's equality is defined by the borderSide and borderRadius
      const UnderlineInputBorder underlineInputBorderRadius =
          UnderlineInputBorder(
        borderSide: BorderSide(color: Colors.red),
        borderRadius: BorderRadius.only(
          topLeft: Radius.circular(5.0),
          topRight: Radius.circular(5.0),
        ),
      );
      expect(
        underlineInputBorderRadius,
        const UnderlineInputBorder(
          borderSide: BorderSide(color: Colors.red),
          borderRadius: BorderRadius.only(
            topLeft: Radius.circular(5.0),
            topRight: Radius.circular(5.0),
          ),
        ),
      );
      expect(
        underlineInputBorderRadius,
        isNot(
          const UnderlineInputBorder(
            borderSide: BorderSide(color: Colors.red),
            borderRadius: BorderRadius.only(
              topLeft: Radius.circular(6.0),
              topRight: Radius.circular(6.0),
            ),
          ),
        ),
      );
    });

    test('UnderlineInputBorder hashCodes', () {
      // UnderlineInputBorder's hashCode is defined only by the borderSide
      const UnderlineInputBorder underlineInputBorder =
          UnderlineInputBorder(borderSide: BorderSide(color: Colors.blue));
      expect(
          underlineInputBorder.hashCode,
          const UnderlineInputBorder(borderSide: BorderSide(color: Colors.blue))
              .hashCode);
      expect(underlineInputBorder.hashCode,
          isNot(const UnderlineInputBorder().hashCode));
      // UnderlineInputBorder's hashCode is defined by the borderSide and borderRadius
      const UnderlineInputBorder underlineInputBorderRadius =
          UnderlineInputBorder(
        borderSide: BorderSide(color: Colors.red),
        borderRadius: BorderRadius.only(
          topLeft: Radius.circular(5.0),
          topRight: Radius.circular(5.0),
        ),
      );
      expect(
        underlineInputBorderRadius.hashCode,
        const UnderlineInputBorder(
          borderSide: BorderSide(color: Colors.red),
          borderRadius: BorderRadius.only(
            topLeft: Radius.circular(5.0),
            topRight: Radius.circular(5.0),
          ),
        ).hashCode,
      );
      expect(
        underlineInputBorderRadius.hashCode,
        isNot(
          const UnderlineInputBorder(
            borderSide: BorderSide(color: Colors.red),
            borderRadius: BorderRadius.only(
              topLeft: Radius.circular(6.0),
              topRight: Radius.circular(6.0),
            ),
          ).hashCode,
        ),
      );
    });
  });
}