Tests annotation DurationField

Classe Ticket

class Ticket(models.Model):
    active_at = models.DateTimeField()
    duration = models.DurationField()

    def __str__(self):
        return '{} - {}'.format(self.active_at, self.duration)

class NonAggregateAnnotationTestCase(TestCase)

import datetime
from decimal import Decimal

from django.core.exceptions import FieldDoesNotExist, FieldError
from django.db.models import (
    BooleanField, CharField, Count, DateTimeField, ExpressionWrapper, F, Func,
    IntegerField, NullBooleanField, OuterRef, Q, Subquery, Sum, Value,
)
from django.db.models.expressions import RawSQL
from django.db.models.functions import Length, Lower
from django.test import TestCase, skipUnlessDBFeature

from .models import (
    Author, Book, Company, DepartmentStore, Employee, Publisher, Store, Ticket,
)


def cxOracle_py3_bug(func):
    """
    There's a bug in Django/cx_Oracle with respect to string handling under
    Python 3 (essentially, they treat Python 3 strings as Python 2 strings
    rather than unicode). This makes some tests here fail under Python 3, so
    we mark them as expected failures until someone fixes them in #23843.
    """
    from unittest import expectedFailure
    from django.db import connection
    return expectedFailure(func) if connection.vendor == 'oracle' else func


class NonAggregateAnnotationTestCase(TestCase):

    @classmethod
    def setUpTestData(cls):
        cls.a1 = Author.objects.create(name='Adrian Holovaty', age=34)
        cls.a2 = Author.objects.create(name='Jacob Kaplan-Moss', age=35)
        cls.a3 = Author.objects.create(name='Brad Dayley', age=45)
        cls.a4 = Author.objects.create(name='James Bennett', age=29)
        cls.a5 = Author.objects.create(name='Jeffrey Forcier', age=37)
        cls.a6 = Author.objects.create(name='Paul Bissex', age=29)
        cls.a7 = Author.objects.create(name='Wesley J. Chun', age=25)
        cls.a8 = Author.objects.create(name='Peter Norvig', age=57)
        cls.a9 = Author.objects.create(name='Stuart Russell', age=46)

test_mixed_type_annotation_date_interval

def test_mixed_type_annotation_date_interval(self):
    active = datetime.datetime(2015, 3, 20, 14, 0, 0)
    duration = datetime.timedelta(hours=1)
    expires = datetime.datetime(2015, 3, 20, 14, 0, 0) + duration
    Ticket.objects.create(active_at=active, duration=duration)
    t = Ticket.objects.annotate(
        expires=ExpressionWrapper(F('active_at') + F('duration'), output_field=DateTimeField())
    ).first()
    self.assertEqual(t.expires, expires)