fix: raise most recent exception when not able to fetch query job after starting the job (#1362)

* fix: raise most recent exception when not able to fetch query job after starting the job Towards internal issue 247809965 * update unit test * revert most changes to the test and explain why we're looking for a different exception from the original 'conflict'

Author: tswast

google/cloud/bigquery/_job_helpers.py

@@ -105,7 +105,7 @@ def do_query():
  timeout=timeout,
  )
  except core_exceptions.GoogleAPIError: # (includes RetryError)
- raise create_exc
+ raise
  else:
  return query_job
  else:

tests/unit/test_client.py

@@ -5092,12 +5092,14 @@ def test_query_job_rpc_fail_w_conflict_random_id_job_fetch_fails(self):
  QueryJob, "_begin", side_effect=job_create_error
  )
  get_job_patcher = mock.patch.object(
- client, "get_job", side_effect=DataLoss("we lost yor job, sorry")
+ client, "get_job", side_effect=DataLoss("we lost your job, sorry")
  )
 
  with job_begin_patcher, get_job_patcher:
- # If get job request fails, the original exception should be raised.
- with pytest.raises(Conflict, match="Job already exists."):
+ # If get job request fails but supposedly there does exist a job
+ # with this ID already, raise the exception explaining why we
+ # couldn't recover the job.
+ with pytest.raises(DataLoss, match="we lost your job, sorry"):
  client.query("SELECT 1;", job_id=None)
 
  def test_query_job_rpc_fail_w_conflict_random_id_job_fetch_succeeds(self):