mock function with variable number of aguments using NSubstitute

Question

I have an interface with the following method:

bool ProcessActions(int actionTypeId, out List<int> ints, params object[] actionParameters);

Now how can mock this method to return a value using NSubstitute? Here is what I've tried:

    this.actionOperationsMock.ProcessActions(Arg.Any<int>(), out List<int> _, Arg.Any<int>(), Arg.Any<int>(), Arg.Any<int>(), Arg.Any<DateTime>(), Arg.Any<DateTime>(), Arg.Any<string>()).Returns(
        x =>
            {
                x[1] = null;
                return true;
            });

I've tried to mock it only with the first two parameters, but in my tests, this method is returning false.

Did you try to use `Arg.Any – MakePeaceGreatAgain Jan 31 '19 at 09:03 — MakePeaceGreatAgain, Jan 31 '19 at 09:03
Why won't you use ReturnsForAnyArgs? – LukaszBalazy Jan 31 '19 at 09:09 — LukaszBalazy, Jan 31 '19 at 09:09

score 1 · Accepted Answer · answered Jan 31 '19 at 09:12

I'd advise to use ReturnsForAnyArgs since you are going to mock each one of parameters and params object[] don't have to be mocked in that case since params allow 0 arguments.

mock.ProcessActions(Arg.Any<int>(), out Arg.Any<List<int>>()).ReturnsForAnyArgs(
            x =>
            {
                x[1] = null;
                return true;
            });

        var res = mock.ProcessActions(1, out var list, 1, 1, 1 , DateTime.Now, DateTime.Now.AddHours(2), "");

mock function with variable number of aguments using NSubstitute

1 Answers1