persist_letter saves address correctly to database

the `to` field stores either the phone number or the email address
of the recipient - it's a bit more complicated for letters, since
there are address lines 1 through 6, and a postcode. In utils, they're
stored alongside the personalisation, and we have to ensure that when
we persist to the database we keep as much parity with utils to make
our work easier. Aside from sending, the `to` field is also used to
show recipients on the front end report pages - we've decided that the
best thing to store here is address_line_1 - which is probably going to
be either a person's name, company name, or PO box number

Also, a lot of tests and test cleanup - I added create_template and
create_notification functions in db.py, so if you're creating new
fixtures you can use these functions, and you won't need to pass
notify_db and notify_db_session around, huzzah!

also removed create param from sample_notification since it's not used
anywhere

tests/app/celery/test_tasks.py

@@ -1,6 +1,6 @@
 import uuid
 from datetime import datetime
-from unittest.mock import Mock, ANY
+from unittest.mock import Mock, ANY, call
 
 import pytest
 from freezegun import freeze_time
@@ -17,6 +17,7 @@ from app.celery.tasks import (
     process_row,
     send_sms,
     send_email,
+    persist_letter,
     get_template_class
 )
 from app.dao import jobs_dao, services_dao
@@ -41,20 +42,16 @@ class AnyStringWith(str):
 mmg_error = {'Error': '40', 'Description': 'error'}
 
 
-def _notification_json(template, to, personalisation=None, job_id=None, row_number=None):
-    notification = {
+def _notification_json(template, to, personalisation=None, job_id=None, row_number=0):
+    return {
         "template": str(template.id),
         "template_version": template.version,
         "to": to,
-        "notification_type": template.template_type
+        "notification_type": template.template_type,
+        "personalisation": personalisation or {},
+        "job": job_id and str(job_id),
+        "row_number": row_number
     }
-    if personalisation:
-        notification.update({"personalisation": personalisation})
-    if job_id:
-        notification.update({"job": str(job_id)})
-    if row_number:
-        notification['row_number'] = row_number
-    return notification
 
 
 def test_should_have_decorated_tasks_functions():
@@ -263,6 +260,42 @@ def test_should_process_email_job(email_job_with_placeholders, mocker):
     assert job.job_status == 'finished'
 
 
+@freeze_time("2016-01-01 11:09:00.061258")
+def test_should_process_letter_job(sample_letter_job, mocker):
+    csv = """address_line_1,address_line_2,address_line_3,address_line_4,postcode,name
+    A1,A2,A3,A4,A_POST,Alice
+    """
+    s3_mock = mocker.patch('app.celery.tasks.s3.get_job_from_s3', return_value=csv)
+    mocker.patch('app.celery.tasks.send_email.apply_async')
+    process_row_mock = mocker.patch('app.celery.tasks.process_row')
+    mocker.patch('app.celery.tasks.create_uuid', return_value="uuid")
+
+    process_job(sample_letter_job.id)
+
+    s3_mock.assert_called_once_with(
+        str(sample_letter_job.service.id),
+        str(sample_letter_job.id)
+    )
+
+    row_call = process_row_mock.mock_calls[0][1]
+
+    assert row_call[0] == 0
+    assert row_call[1] == ['A1', 'A2', 'A3', 'A4', None, None, 'A_POST']
+    assert dict(row_call[2]) == {
+        'addressline1': 'A1',
+        'addressline2': 'A2',
+        'addressline3': 'A3',
+        'addressline4': 'A4',
+        'postcode': 'A_POST'
+    }
+    assert row_call[4] == sample_letter_job
+    assert row_call[5] == sample_letter_job.service
+
+    assert process_row_mock.call_count == 1
+
+    assert sample_letter_job.job_status == 'finished'
+
+
 def test_should_process_all_sms_job(sample_job,
                                     sample_job_with_placeholdered_template,
                                     mocker):
@@ -853,6 +886,47 @@ def test_send_sms_does_not_send_duplicate_and_does_not_put_in_retry_queue(sample
     assert not retry.called
 
 
+def test_persist_letter_saves_letter_to_database(sample_letter_job, mocker):
+    personalisation = {
+        'addressline1': 'Foo',
+        'addressline2': 'Bar',
+        'addressline3': 'Baz',
+        'addressline4': 'Wibble',
+        'addressline5': 'Wobble',
+        'addressline6': 'Wubble',
+        '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()
+    created_at = datetime.utcnow()
+
+    persist_letter(
+        sample_letter_job.service_id,
+        notification_id,
+        encryption.encrypt(notification_json),
+        created_at
+    )
+
+    notification_db = Notification.query.one()
+    assert notification_db.id == notification_id
+    assert notification_db.to == 'Foo'
+    assert notification_db.job_id == sample_letter_job.id
+    assert notification_db.template_id == sample_letter_job.template.id
+    assert notification_db.template_version == sample_letter_job.template.version
+    assert notification_db.status == 'created'
+    assert notification_db.created_at == created_at
+    assert notification_db.notification_type == 'letter'
+    assert notification_db.sent_at is None
+    assert notification_db.sent_by is None
+    assert notification_db.personalisation == personalisation
+
+
 @pytest.mark.parametrize('template_type, expected_class', [
     (SMS_TYPE, SMSMessageTemplate),
     (EMAIL_TYPE, WithSubjectTemplate),