Add tests for letters as pdf permission

- test that `create_letters_pdf` only gets called when `letters_as_pdf` permission set
- test that `build_dvla_file` does not get called when `letters_as_pdf` permission set
- test creating the pdf call to notifications template preview service
- test uploading the data to s3 calls upload_letters_pdf function

tests/app/celery/test_tasks.py

@@ -9,8 +9,9 @@ from flask import current_app
 from freezegun import freeze_time
 from requests import RequestException
 from sqlalchemy.exc import SQLAlchemyError
-from celery.exceptions import Retry
+from celery.exceptions import Retry, MaxRetriesExceededError
 from botocore.exceptions import ClientError
+from sqlalchemy.orm.exc import NoResultFound
 from notifications_utils.template import SMSMessageTemplate, WithSubjectTemplate, LetterDVLATemplate
 
 from app import (encryption, DATETIME_FORMAT)
@@ -20,6 +21,9 @@ from app.celery.scheduled_tasks import check_job_status
 from app.celery.tasks import (
     build_dvla_file,
     create_dvla_file_contents_for_job,
+    create_letters_pdf,
+    get_letters_pdf,
+    job_complete,
     process_job,
     process_row,
     save_sms,
@@ -32,7 +36,7 @@ from app.celery.tasks import (
     send_inbound_sms_to_service,
 )
 from app.config import QueueNames
-from app.dao import jobs_dao, services_dao
+from app.dao import jobs_dao, services_dao, service_permissions_dao
 from app.models import (
     Job,
     Notification,
@@ -47,6 +51,7 @@ from app.models import (
     SMS_TYPE
 )
 
+from tests.conftest import set_config_values
 from tests.app import load_example_csv
 from tests.app.conftest import (
     sample_service as create_sample_service,
@@ -94,6 +99,7 @@ def test_should_have_decorated_tasks_functions():
     assert save_sms.__wrapped__.__name__ == 'save_sms'
     assert save_email.__wrapped__.__name__ == 'save_email'
     assert save_letter.__wrapped__.__name__ == 'save_letter'
+    assert create_letters_pdf.__wrapped__.__name__ == 'create_letters_pdf'
 
 
 @pytest.fixture
@@ -1039,6 +1045,50 @@ def test_save_letter_saves_letter_to_database(mocker, notify_db_session):
     assert notification_db.reply_to_text == "Address contact"
 
 
+def test_save_letter_saves_letter_calls_create_letters_as_pdf_with_letters_as_pdf_permission(
+        mocker, notify_db_session, sample_letter_job):
+    service_permissions_dao.dao_add_service_permission(sample_letter_job.service.id, 'letters_as_pdf')
+    mock_create_letters_pdf = mocker.patch('app.celery.tasks.create_letters_pdf.apply_async')
+
+    personalisation = {
+        'addressline1': 'Foo',
+        'addressline2': 'Bar',
+        'postcode': 'Flob',
+    }
+    notification_json = _notification_json(
+        template=sample_letter_job.template,
+        to='Foo',
+        personalisation=personalisation,
+        job_id=sample_letter_job.id,
+        row_number=1
+    )
+    notification_id = uuid.uuid4()
+
+    save_letter(
+        sample_letter_job.service_id,
+        notification_id,
+        encryption.encrypt(notification_json),
+    )
+
+    assert mock_create_letters_pdf.called
+    mock_create_letters_pdf.assert_called_once_with(
+        [str(notification_id)],
+        queue=QueueNames.CREATE_LETTERS_PDF
+    )
+
+
+def test_job_complete_does_not_call_build_dvla_file_with_letters_as_pdf_permission(
+        mocker, notify_db_session, sample_letter_job):
+    service_permissions_dao.dao_add_service_permission(sample_letter_job.service.id, 'letters_as_pdf')
+    mock_build_dvla_files = mocker.patch('app.celery.tasks.build_dvla_file.apply_async')
+
+    job_complete(sample_letter_job, sample_letter_job.service, sample_letter_job.template.template_type)
+
+    assert not sample_letter_job.service.research_mode
+    assert not mock_build_dvla_files.called
+    assert sample_letter_job.job_status == JOB_STATUS_FINISHED
+
+
 def test_should_cancel_job_if_service_is_inactive(sample_service,
                                                   sample_job,
                                                   mocker):
@@ -1455,3 +1505,83 @@ def test_process_incomplete_job_letter(mocker, sample_letter_template):
 
     assert mock_build_dvla.called
     assert mock_letter_saver.call_count == 8
+
+
+@pytest.mark.parametrize('personalisation', [{'name': 'test'}, None])
+def test_get_letters_pdf_calls_notifications_template_preview_service_correctly(
+        notify_api, mocker, client, sample_letter_template, personalisation):
+    contact_block = 'Mr Foo,\n1 Test Street,\nLondon\nN1'
+    dvla_org_id = '002'
+
+    with set_config_values(notify_api, {
+        'TEMPLATE_PREVIEW_API_HOST': 'http://localhost/notifications-template-preview',
+        'TEMPLATE_PREVIEW_API_KEY': 'test-key'
+    }):
+        with requests_mock.Mocker() as request_mock:
+            mock_post = request_mock.post(
+                'http://localhost/notifications-template-preview/print.pdf', content=b'\x00\x01', status_code=200)
+
+            get_letters_pdf(
+                sample_letter_template, contact_block=contact_block, org_id=dvla_org_id, values=personalisation)
+
+    assert mock_post.last_request.json() == {
+        'values': personalisation,
+        'letter_contact_block': contact_block,
+        'dvla_org_id': dvla_org_id,
+        'template': {
+            'subject': sample_letter_template.subject,
+            'content': sample_letter_template.content
+        }
+    }
+
+
+def test_create_letters_pdf_calls_upload_letters_pdf(mocker, sample_letter_notification):
+    mocker.patch('app.celery.tasks.get_letters_pdf', return_value=b'\x00\x01')
+    mock_s3 = mocker.patch('app.celery.tasks.s3.upload_letters_pdf')
+
+    create_letters_pdf(sample_letter_notification.id)
+
+    mock_s3.assert_called_with(
+        reference=sample_letter_notification.reference,
+        crown=True,
+        filedata=b'\x00\x01'
+    )
+
+
+def test_create_letters_pdf_non_existent_notification(notify_api, mocker, fake_uuid):
+    with pytest.raises(expected_exception=NoResultFound):
+        create_letters_pdf(fake_uuid)
+
+
+def test_create_letters_pdf_handles_request_errors(mocker, sample_letter_notification):
+    mock_get_letters_pdf = mocker.patch('app.celery.tasks.get_letters_pdf', side_effect=RequestException)
+    mock_retry = mocker.patch('app.celery.tasks.create_letters_pdf.retry')
+
+    create_letters_pdf(sample_letter_notification.id)
+
+    assert mock_get_letters_pdf.called
+    assert mock_retry.called
+
+
+def test_create_letters_pdf_handles_s3_errors(mocker, sample_letter_notification):
+    mocker.patch('app.celery.tasks.get_letters_pdf')
+    mock_s3 = mocker.patch('app.celery.tasks.s3.upload_letters_pdf', side_effect=ClientError({}, 'operation_name'))
+    mock_retry = mocker.patch('app.celery.tasks.create_letters_pdf.retry')
+
+    create_letters_pdf(sample_letter_notification.id)
+
+    assert mock_s3.called
+    assert mock_retry.called
+
+
+def test_create_letters_pdf_sets_technical_failure_max_retries(mocker, sample_letter_notification):
+    mock_get_letters_pdf = mocker.patch('app.celery.tasks.get_letters_pdf', side_effect=RequestException)
+    mock_retry = mocker.patch('app.celery.tasks.create_letters_pdf.retry', side_effect=MaxRetriesExceededError)
+    mock_update_noti = mocker.patch('app.celery.tasks.update_notification_status_by_id')
+
+    create_letters_pdf(sample_letter_notification.id)
+
+    assert mock_get_letters_pdf.called
+    assert mock_retry.called
+    assert mock_update_noti.called
+    mock_update_noti.assert_called_once_with(sample_letter_notification.id, 'technical-failure')