public void TestSubStringBeforeBeforeNull()
 {
     var function = new SubStringBeforeFunction();
     Assert.That(function.Evaluate("abcdefg", null), Is.EqualTo("abcdefg"));
 }
 public void TestSubStringBeforeNonExistingBefore()
 {
     var function = new SubStringBeforeFunction();
     Assert.That(function.Evaluate("abcdefg", "xyz"), Is.EqualTo("abcdefg"));
 }
 public void TestSubStringBeforeAllNull()
 {
     var function = new SubStringBeforeFunction();
     Assert.That(function.Evaluate(null, null), Is.EqualTo(""));
 }