Refactor the color decode test by using a nested class

[Josef-Friedrich]

This prevents the variables and their value assignments from having to be repeated four times.

Instead of

  @Test
  void testRedFromAlphaHexString() {
    String red200 = "#c8ff0000";

    Color redDecoded = ColorHelper.decode(red200);

    Color alphaRed = new Color(255, 0, 0, 200);
    assertEquals(alphaRed.getRed(), redDecoded.getRed());
  }

  @Test
  void testGreenFromAlphaHexString() {
    String red200 = "#c8ff0000";

    Color redDecoded = ColorHelper.decode(red200);

    Color alphaRed = new Color(255, 0, 0, 200);
    assertEquals(alphaRed.getGreen(), redDecoded.getGreen());
  }

  @Test
  void testBlueFromAlphaHexString() {
    String red200 = "#c8ff0000";

    Color redDecoded = ColorHelper.decode(red200);

    Color alphaRed = new Color(255, 0, 0, 200);
    assertEquals(alphaRed.getBlue(), redDecoded.getBlue());
  }

  @Test
  void testAlphaFromAlphaHexString() {
    String red200 = "#c8ff0000";

    Color redDecoded = ColorHelper.decode(red200);

    Color alphaRed = new Color(255, 0, 0, 200);
    assertEquals(alphaRed.getAlpha(), redDecoded.getAlpha());
  }

DRY Don’t repeat yourself ->

  @Nested
  class DecodeTest
  {
      String red200 = "#c8ff0000";

      Color redDecoded = ColorUtil.decode(red200);

      Color alphaRed = new Color(255, 0, 0, 200);

      @Test
      void testRedFromAlphaHexString() {
        assertEquals(alphaRed.getRed(), redDecoded.getRed());
      }

      @Test
      void testGreenFromAlphaHexString() {
        assertEquals(alphaRed.getGreen(), redDecoded.getGreen());
      }

      @Test
      void testBlueFromAlphaHexString() {
        assertEquals(alphaRed.getBlue(), redDecoded.getBlue());
      }

      @Test
      void testAlphaFromAlphaHexString() {
        assertEquals(alphaRed.getAlpha(), redDecoded.getAlpha());
      }
  }

[Josef-Friedrich]

@Gamebuster19901 thank you for your review! All your suggestions make sense. I have tried to implement all your suggestions. Hopefully I have succeeded.