10

What is the difference between this:

ResultSet set = EasyMock.createNiceMock(ResultSet.class);
EasyMock.expect(set.getInt("col1")).andReturn(1);
EasyMock.expect(set.wasNull()).andReturn(false);
EasyMock.expect(set.getInt("col2")).andReturn(2);
EasyMock.expect(set.wasNull()).andReturn(false);
EasyMock.replay(set);

assertEquals(1, set.getInt("col1"));
assertEquals(false, set.wasNull());
assertEquals(2, set.getInt("col2"));
assertEquals(false, set.wasNull());

And this:

ResultSet set = EasyMock.createNiceMock(ResultSet.class);
EasyMock.expect(set.getInt("col1")).andReturn(1);
EasyMock.expect(set.getInt("col2")).andReturn(2);
EasyMock.expect(set.wasNull()).andReturn(false).times(2);
EasyMock.replay(set);

assertEquals(1, set.getInt("col1"));
assertEquals(false, set.wasNull());
assertEquals(2, set.getInt("col2"));
assertEquals(false, set.wasNull());

?

Note: both sets of code compile and run successfully as jUnit tests. Also, note that the use of a "nice" mock is on purpose here.

daveslab
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2 Answers2

13

To answer the question in your title - there's no difference. Calling x.expect(y).times(3) is exactly the same as calling

x.expect(y);
x.expect(y);
x.expect(y);

(Note that as pointed out by Andy Thomas-Cramer, your specific examples aren't entirely equivalent because the order of calls differ.)

This might just seem like a convenience issue. However there's a distinct difference beyond this: in that the times() case you can pass in the expected number of calls as a variable. Consequently you can make this configurable by some external file, or even simply by a public constant int which you also use to fire off the test harness. It's a lot more flexible than having to explicitly compile the correct number of calls to expect() (and update your code if you now need to test with five workers instead of three).

Andrzej Doyle
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3

The second is simpler to read and write. However, it would fail if the mock were changed to a strict mock, in which order of calls is validated.

Andy Thomas
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  • So you're basically saying that there is no difference, really? I know if it was changed to strict it would matter. – daveslab Sep 20 '11 at 16:05
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    No difference in terms of successful validation, for a nice mock -- but yes, a difference in terms of readability/writability. Consider times(42). And as @Andrzej points out, sometimes you might want the number of calls to be a variable. – Andy Thomas Sep 20 '11 at 16:38