public void ReturnsTrueForAnyInput_WithZeroLeftoverColumns() { int leftover; var toTest = new ExpandoObjectRowFactory <dynamic>(); var result = toTest.MatchesColumns(new[] { "String", "Double", "Decimal", "Int", "Long", "Date" }, out leftover); result.Should().BeTrue("because any and all columns will be matched"); leftover.Should().Be(0, "because all columns get matched, none should be leftover"); }