public void ShouldBeAString()
{
var value = new JsString("a");
Assert.Equal(false, value.IsBoolean());
Assert.Equal(false, value.IsArray());
Assert.Equal(false, value.IsDate());
Assert.Equal(false, value.IsNull());
Assert.Equal(false, value.IsNumber());
Assert.Equal(false, value.IsObject());
Assert.Equal(true, value.IsPrimitive());
Assert.Equal(false, value.IsRegExp());
Assert.Equal(true, value.IsString());
Assert.Equal("a", value.AsString());
Assert.Equal(false, value.IsUndefined());
}