@Test
public void convertValueToString() {

    assertEquals(null, helper.convertValueToString(null));
    assertEquals("true", helper.convertValueToString(true));
    assertEquals("false", helper.convertValueToString(false));
    Date date = new Date();
    assertEquals(format.format(date), helper.convertValueToString(date));
    assertEquals(BigDecimal.ONE.toPlainString(), helper.convertValueToString(BigDecimal.ONE));
    assertEquals(BigInteger.ONE.toString(), helper.convertValueToString(BigInteger.ONE));
    Byte b = Byte.MAX_VALUE;
    assertEquals(b.toString(), helper.convertValueToString(b));
    Double d = 123.456;
    assertEquals(d.toString(), helper.convertValueToString(d));
    Float f = new Float(123.456);
    assertEquals(f.toString(), helper.convertValueToString(f));
    Integer i = 123;
    assertEquals(i.toString(), helper.convertValueToString(i));
    Long l = new Long(123);
    assertEquals(l.toString(), helper.convertValueToString(l));
    Short s = 123;
    assertEquals(s.toString(), helper.convertValueToString(s));
    assertEquals("surprise!", helper.convertValueToString("surprise!"));
}