Unit testing MR without dependency injection

["GOEKE, MATTHEW (AG/1000)" <ma...@monsanto.com>]

Does anyone have any code examples for how they persist join data across multiple input splits and how they test it? Currently I populate a singleton in the setup method of my mapper (along with having jvm reuse turned on for this job) but with no way to have dependency injection into the mapper I am really having a hard time with wrapping a UT around the code. I could have a package scoped setter simply for testing purposes but that just feels dirty to be honest. Any help is greatly appreciated and I have both MRUnit and Mockito at my disposal.

  private BitPackedMarkerMap markerMap = BitPackedMarkerMapSingleton.getInstance().getMarkerMap();
  private int numberOfIndividuals = -999;
  private int numberOfAlleles = -999;

  @Override
  protected void setup(Context context) throws IOException, InterruptedException {
    LongPackedDoubleInteger inputSizes;
    if(markerMap.getSize() == 0){
    FileInputStream scoresInputStream = null;
      try{
        Path[] cacheFiles = DistributedCache.getLocalCacheFiles(context.getConfiguration());
        if (cacheFiles != null && cacheFiles.length > 0){
          scoresInputStream = new FileInputStream(cacheFiles[0].toString());
          inputSizes = markerMap.parse(scoresInputStream);
          numberOfIndividuals = inputSizes.getInt1();
          numberOfAlleles = inputSizes.getInt2();
        }
      } catch (IOException e){
        System.err.println("Exception reading DistributedCache: " + e);
        throw e;
      }finally {
        if(scoresInputStream != null){
          scoresInputStream.close();
        }
      }
    }
  }




Matt
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