Question

I have this class called Table:

class Table {     public string Name     {         get         {             return this.wrapper.Eval(//some command);              //wrapper is pass in by the ctor and is a COM object.         }     } } 

which is used in this class:

class Map {   public Map MapTable(Table table)   {      return new Map(table.Name);   } } 

I want to test MapTable command, should I be mocking Table or should I mock the wrapper object that is used by the table object.

I was thinking something like this

 Test()  {    Mock<ITable> mocktable = new Mock<ITable>(//pass in the wrapper object);    mocktable.ExpectGet(n => n.Name).Returns('Hello World');     ITable table = mocktable.object;    Map mymap = Map.MapTable(table);  } 

Would that be correct?

Answer 1

Beyond the fact that there is usually no one perfect testing solution, I’d first go for mocking the COM object: there should be a interface available and you’ll probably want to test everything ‘above’ it.

If the Table contains non-trivial code (e.g. within the Eval(); anything with conditionals; or e.g. parsing using a Culture) you might want to have a mock of it as you show in your example.