I've figured out the details of how to do it. I'll post a generalized
tutorial to the wiki this evening.


-- 
- kate = masukomi
http://weblog.masukomi.org/


On 9/21/07, kate rhodes <[EMAIL PROTECTED]> wrote:
> On 9/21/07, Enis Soztutar <[EMAIL PROTECTED]> wrote:
> > Hi,
> >
> > You can develop your unit tests by using classes under src/test. Infact
> > you may find MiniMRCluster and MiniMRDFS very useful. Alternatively you
> > may invoke the program in local mode, with a smaller input to check the
> > outcomes.
>
> Anything that involves communicating with another class is NOT a unit
> test. It's an integration test because problems in that other class
> could give false failures. Also, bugs you're unknowingly relying on in
> the other class could provide false passes.  If, for example, someone
> introduced a bug in MiniMRCluster and I was relying on it in my test
> for my Mapper then in would cause my test to fail. And that's bull. It
> means I wasn't testing my Mapper, I was testing the integration of my
> Mapper with the MiniMRCluster with probably 40 or 50 other classes
> that get tied in.
>
> A unit test *has* to be totally isolated. The class under test should
> be allowed no communication with any other object that isn't a
> mock-object otherwise the problems noted above crop up. I need to know
> that the class I'm testing is written correctly regardless of what
> other bugs may or may not have been introduced in other classes.
> Otherwise I see my class fail and start wondering what I've screwed up
> in it, and what needs debugging even if my class is 100% correct. I'm
> not willing to waste my time hunting the causes of bogus failures when
> i could have a test suite that actually told me the correct class that
> had the bug in it.
>
> There are good reasons to write integration tests but you have to
> understand that they are dramatically different beasts than unit
> tests.
>
>
> I had already found those classes you mentioned, but, like I said, I
> haven't been able to find any examples of a UNIT test of a Mapper or
> Reducer (integration tests don't count).
>
> --
> - kate = masukomi
> http://weblog.masukomi.org/
>

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