@Test
  public void testInitTableMapperJob1() throws Exception {
    Configuration configuration = new Configuration();
    Job job = Job.getInstance(configuration, "tableName");
    // test
    TableMapReduceUtil.initTableMapperJob("Table", new Scan(), Import.Importer.class, Text.class,
      Text.class, job, false, WALInputFormat.class);
    assertEquals(WALInputFormat.class, job.getInputFormatClass());
    assertEquals(Import.Importer.class, job.getMapperClass());
    assertEquals(LongWritable.class, job.getOutputKeyClass());
    assertEquals(Text.class, job.getOutputValueClass());
    assertNull(job.getCombinerClass());
    assertEquals("Table", job.getConfiguration().get(TableInputFormat.INPUT_TABLE));
  }
Test different variants of initTableMapperJob method
hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapreduce/TestTableMapReduceUtil.java