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https://issues.apache.org/jira/browse/MAPREDUCE-2002?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12897547#action_12897547
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David Rosenstrauch commented on MAPREDUCE-2002:
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Yes, it does look like a dupe. (I did do a search through Jira before filing
this bug, but that bug didn't turn up in my search for some reason.)
> MRUnit driver classes should provide ability to set a configuration object to
> be passed into the mapper/reducer
> ---------------------------------------------------------------------------------------------------------------
>
> Key: MAPREDUCE-2002
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2002
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: contrib/mrunit
> Affects Versions: 0.20.2
> Reporter: David Rosenstrauch
> Priority: Minor
>
> Short description:
> Enhance the org.apache.hadoop.mrunit.mapreduce.MapDriver, ReduceDriver, and
> MapReduceDriver unit test driver classes to contain "setConfiguration" and
> "withConfiguration" methods for passing in user-supplied
> org.apache.hadoop.conf.Configuration objects, and have those configuration
> objects eventually get passed on to the Context objects that are passed in to
> the mapper/reducer "setup" methods. (Rather than passing in an empty
> Configuration object, as is being done now.)
> Long description:
> The MRUnit driver classes (i.e., MapDriver, ReduceDriver, and
> MapReduceDriver) ought to be enhanced to contain methods for setting a
> Configuration object to be used by the mapper/reducer being tested - i.e.,
> setConfiguration() and withConfiguration().
> The only way to effectively pass parameters into a mapper or reducer is by
> setting properties on a configuration object, which the mapper/reducer can
> then retrieve in their "setup" step, and use to customize its operation. As
> a result, specific mappers/reducers may require the presence of specific
> configuration properties/parameters in order to function correctly (or at
> all). (I am currently coding such a reducer right now.)
> Testing such a mapper/reducer thus requires that the unit testing framework
> used provide the ability to pass in user-supplied Configuration objects to
> them so that they can be tested with appropriate parameter values. However,
> MRUnit currently does not provide this ability. (All mappers/reducers are
> always passed an empty configuration object.) And there is not even
> currently any (easy) way for the end-user to fix this problem by creating a
> simple sub-class that supplies this functionality, as such subclasses would
> require a substantial reimplementation/override of several MRUnit framework
> classes.
> I believe this something that is not too difficult to fix in the MRUnit
> framework code, however, and would greatly help the usability of MRUnit.
> Although I don't have time to code this enhancement right now, if
> needed/preferred I could squeeze out some time to code up a patch for this.
> If that's needed, please let me know.
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