public void AppendIntTest()
        {
            Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
              StringBuilder stringBuilder = new StringBuilder();

              stringBuilder.AppendNumber(1234567890);
              Assert.AreEqual("1234567890", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(-1234567890);
              Assert.AreEqual("-1234567890", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234567890, AppendNumberOptions.None);
              Assert.AreEqual("1234567890", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234567890, AppendNumberOptions.PositiveSign);
              Assert.AreEqual("+1234567890", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234567890, AppendNumberOptions.NumberGroup);
              Assert.AreEqual("1,234,567,890", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234567890, AppendNumberOptions.PositiveSign | AppendNumberOptions.NumberGroup);
              Assert.AreEqual("+1,234,567,890", stringBuilder.ToString());
        }
        public void AppendFloatTest()
        {
            Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
              StringBuilder stringBuilder = new StringBuilder();

              stringBuilder.Clear();
              stringBuilder.AppendNumber(float.NaN);
              Assert.AreEqual("NaN", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(float.PositiveInfinity);
              Assert.AreEqual("+Infinity", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(float.NegativeInfinity);
              Assert.AreEqual("-Infinity", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234.12645f);
              Assert.AreEqual("1234.13", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1.23456f, 4, AppendNumberOptions.NumberGroup);
              Assert.AreEqual("1.2346", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(-1234.12645f);
              Assert.AreEqual("-1234.12", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234.12645f, AppendNumberOptions.None);
              Assert.AreEqual("1234.13", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234.12645f, AppendNumberOptions.PositiveSign);
              Assert.AreEqual("+1234.13", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234.12645f, AppendNumberOptions.NumberGroup);
              Assert.AreEqual("1,234.13", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234.12645f, AppendNumberOptions.PositiveSign | AppendNumberOptions.NumberGroup);
              Assert.AreEqual("+1,234.13", stringBuilder.ToString());

              stringBuilder.Clear();
              stringBuilder.AppendNumber(123412600f, AppendNumberOptions.PositiveSign | AppendNumberOptions.NumberGroup);
              Assert.AreEqual("+123,412,600.00", stringBuilder.ToString()); // Note: Value differs because of limited precision of floating-point.

              // If the number is too long the AppendNumber falls back to StringBuilder.Append() and uses
              // exponential notation.
              stringBuilder.Clear();
              stringBuilder.AppendNumber(1234126000000000000000f);
              Assert.IsTrue(stringBuilder.ToString().Length > 0);
        }