test_migration.py

old_db = ... # connect to old db
new_db = ... # connect new migrated db

def bluebook_position_test_data(old_doc, new_doc):
  """
  tests whether old_doc (from bluebook_position) contains the same information than new_doc (from scores)
  """
  # do something here
  
def test_bluebook_position():
  """
  tests whether migration went OK for bluebook_position
  """
  def query_builder(old_doc):
    return {'_id': old_doc['bluebook_id']}
    
  test_coll(src_coll=old_db.bluebook_position, 
            dst_coll=new_db.scores, 
            tests=[bluebook_position_test_data], 
            query_builder=query_builder)
  
            
def test_coll(src_coll, dst_coll, tests, query_builder, assert_same_size=True):
  """
  tests whether all documents in src_collection match with at least one document of dst_collection 
  and passes all the tests in tests
  """
  for old_doc in src_coll.find():
    query = query_builder(old_doc)
    new_doc = dst_coll.find_one(query)
    assert new_doc is not None # src_coll included in dst_coll
    for test in tests:
      test(old_doc, new_doc)
  
  if assert_same_size:
    assert src_coll.count() == dst_coll.count()