Return different instances for each call using rhino mocks

Question

I've got this code:

Expect.Call(factory.CreateOrder())
    .Return(new Order())
    .Repeat.Times(4);

When this is called four times, every time the same instance is returned. I want difference instances to be returned. I would like to be able to do something like:

Expect.Call(factory.CreateOrder())
    .Return(() => new Order())
    .Repeat.Times(4);

Can this be done in some way?

Csharpenter, what do you mean? I use _mocker.ReplayAll(); and _mocker.VerifyAll();... — Allrameest, Jan 28 '11 at 15:39

score 14 · Accepted Answer · answered Jan 28 '11 at 15:33

14

Instead of using

.Return(new Order());

Try using

.Do((Func<Order>)delegate() { return new Order(); });

This will call the delegate each time, creating a new object.

answered Jan 28 '11 at 15:33

Pedro

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One thing to look out for is that the function signature has to match the original call even if you aren't going to pass it along. Mine ended up looking something like this: `.Stub(m => m.Load(docId)).Do((Func)(arg => GetDocument()));` Notice how the long is just dumped. Otherwise you get an exception. – Uriah Blatherwick Jun 06 '12 at 18:55

score 2 · Answer 2 · answered May 03 '12 at 14:24

Patrick Steele suggested this extenstion method:

public static IMethodOptions<T> Return<T>(this IMethodOptions<T> opts, Func<T> factory)
{
    opts.Return(default(T));
    opts.WhenCalled(mi => mi.ReturnValue = factory());
    return opts;
}

See his blog entry for more details.

Yann Trevin · Answer 3 · 2011-01-28T14:24:58.900

Repeat 4 times your expectation by specifying a different return value each time (notice the Repeat.Once())

for (int i = 0; i < 4; i++)
   Expect.Call(factory.CreateOrder()).Repeat.Once().Return(new Order());

UPDATE: I believe the following will work as well:

Expect.Call(factory.CreateOrder())
  .Repeat.Once().Return(new Order())
  .Repeat.Once().Return(new Order())
  .Repeat.Once().Return(new Order())
  .Repeat.Once().Return(new Order());

Return different instances for each call using rhino mocks

3 Answers3