diff --git a/crashreports/tests.py b/crashreports/tests.py
index 31a24b5..2267a79 100644
--- a/crashreports/tests.py
+++ b/crashreports/tests.py
@@ -1,17 +1,18 @@
+"""Test the API for crashreports, devices, heartbeats and logfiles."""
 import os
 import tempfile
 
 from django.contrib.auth.models import User
 from django.urls import reverse
-from rest_framework.test import APITestCase
-from rest_framework.test import APIClient
+
 from rest_framework import status
+from rest_framework.test import APIClient, APITestCase
 
 from crashreports.models import Crashreport
 
 
 class InvalidCrashTypeError(BaseException):
-    """Invalid crash type encountered
+    """Invalid crash type encountered.
 
     The valid crash type values (strings) are:
       - 'crash';
@@ -23,11 +24,18 @@
     """
 
     def __init__(self, crash_type):
+        """Initialise the exception using the crash type to build a message.
+
+        Args:
+            crash_type: The invalid crash type.
+        """
         super(InvalidCrashTypeError, self).__init__(
             '{} is not a valid crash type'.format(crash_type))
 
 
-class Dummy(object):
+class Dummy():
+    """Dummy values for devices, heartbeats and crashreports."""
+
     DEFAULT_DUMMY_DEVICE_REGISTER_VALUES = {
         'board_date': '2015-12-15T01:23:45Z',
         'chipset': 'Qualcomm MSM8974PRO-AA',
@@ -62,45 +70,42 @@
 
     @staticmethod
     def _update_copy(original, update):
-        """Merge fields of update into a copy of original"""
+        """Merge fields of update into a copy of original."""
         data = original.copy()
         data.update(update)
         return data
 
     @staticmethod
     def device_register_data(**kwargs):
-        """
-            Return the data required to register a device.
+        """Return the data required to register a device.
 
-            Use the values passed as keyword arguments or default to
-            the ones from `Dummy.DEFAULT_DUMMY_DEVICE_REGISTER_VALUES`.
+        Use the values passed as keyword arguments or default to the ones
+        from `Dummy.DEFAULT_DUMMY_DEVICE_REGISTER_VALUES`.
         """
         return Dummy._update_copy(
             Dummy.DEFAULT_DUMMY_DEVICE_REGISTER_VALUES, kwargs)
 
     @staticmethod
     def heartbeat_data(**kwargs):
-        """
-            Return the data required to create a heartbeat.
+        """Return the data required to create a heartbeat.
 
-            Use the values passed as keyword arguments or default to
-            the ones from `Dummy.DEFAULT_DUMMY_HEARTBEAT_VALUES`.
+        Use the values passed as keyword arguments or default to the ones
+        from `Dummy.DEFAULT_DUMMY_HEARTBEAT_VALUES`.
         """
         return Dummy._update_copy(Dummy.DEFAULT_DUMMY_HEARTBEAT_VALUES, kwargs)
 
     @staticmethod
     def crashreport_data(report_type=None, **kwargs):
-        """
-            Return the data required to create a crashreport.
+        """Return the data required to create a crashreport.
 
-            Use the values passed as keyword arguments or default to
-            the ones from `Dummy.DEFAULT_DUMMY_CRASHREPORTS_VALUES`.
+        Use the values passed as keyword arguments or default to the ones
+        from `Dummy.DEFAULT_DUMMY_CRASHREPORTS_VALUES`.
 
-            Args:
-                report_type (str, optional): A valid value from
-                    `Dummy.CRASH_TYPE_TO_BOOT_REASON_MAP.keys()` that will
-                    define the boot reason if not explicitly defined in the
-                    keyword arguments already.
+        Args:
+            report_type (str, optional): A valid value from
+                `Dummy.CRASH_TYPE_TO_BOOT_REASON_MAP.keys()` that will
+                define the boot reason if not explicitly defined in the
+                keyword arguments already.
         """
         data = Dummy._update_copy(
             Dummy.DEFAULT_DUMMY_CRASHREPORTS_VALUES, kwargs)
@@ -112,151 +117,164 @@
         return data
 
 
-class DeviceTestCase(APITestCase):
-
-    def setUp(self):
-        self.url = reverse("api_v1_register_device")
-
-    def test(self):
-        request = self.client.post(self.url, Dummy.device_register_data())
-        self.assertTrue("token" in request.data)
-        self.assertTrue("uuid" in request.data)
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
-
-    def test_create_missing_fields(self):
-        request = self.client.post(self.url)
-        self.assertEqual(request.status_code, status.HTTP_400_BAD_REQUEST)
-
-    def test_create_missing_board_date(self):
-        data = Dummy.device_register_data()
-        data.pop('board_date')
-        request = self.client.post(self.url, data)
-        self.assertEqual(request.status_code, status.HTTP_400_BAD_REQUEST)
-
-    def test_create_missing_chipset(self):
-        data = Dummy.device_register_data()
-        data.pop('chipset')
-        request = self.client.post(self.url, data)
-        self.assertEqual(request.status_code, status.HTTP_400_BAD_REQUEST)
-
-    def test_create_invalid_board_date(self):
-        data = Dummy.device_register_data()
-        data['board_date'] = 'not_a_valid_date'
-        request = self.client.post(self.url, data)
-        self.assertEqual(request.status_code, status.HTTP_400_BAD_REQUEST)
-
-    def test_create_non_existent_time_board_date(self):
-        """
-        Test the resolution of a naive date-time in which the Europe/Amsterdam daylight saving
-        time transition moved the time "forward".
-        """
-        data = Dummy.device_register_data()
-        # In 2017, the Netherlands changed from CET to CEST on March, 26 at 02:00
-        data['board_date'] = '2017-03-26 02:34:56'
-        request = self.client.post(self.url, data)
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
-
-    def test_create_ambiguous_time_board_date(self):
-        """
-        Test the resolution of a naive date-time in which the Europe/Amsterdam daylight saving
-        time transition moved the time "backward".
-        """
-        data = Dummy.device_register_data()
-        # In 2017, the Netherlands changed from CEST to CET on October, 29 at 03:00
-        data['board_date'] = '2017-10-29 02:34:56'
-        request = self.client.post(self.url, data)
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
-
-
 class DeviceRegisterAPITestCase(APITestCase):
-    """Base class that offers device registration as well as base users
-
-    Attributes:
-        number_of_devices_created (int): The number of devices created in the
-            database.
-    """
+    """Base class that offers a device registration method."""
 
     REGISTER_DEVICE_URL = "api_v1_register_device"
 
     def setUp(self):
-        self.number_of_devices_created = 0
+        """Create an admin user for accessing the API.
 
-        _, response_data = self._register_device()
-        self.uuid = response_data['uuid']
-        self.token = response_data['token']
-        self.user = APIClient()
-        self.user.credentials(HTTP_AUTHORIZATION='Token ' + self.token)
-
-        _, response_data = self._register_device()
-        self.other_uuid = response_data['uuid']
-        self.other_token = response_data['token']
-        self.other_user = APIClient()
-        self.other_user.credentials(
-            HTTP_AUTHORIZATION='Token ' + self.other_token)
-
-        self.noauth_client = APIClient()
-
-        self.admin_user = User.objects.create_superuser(
+        The APIClient that can be used to make authenticated requests to the
+        server is stored in self.admin.
+        """
+        admin_user = User.objects.create_superuser(
             'somebody', 'somebody@example.com', 'thepassword')
         self.admin = APIClient()
-        self.admin.force_authenticate(self.admin_user)
+        self.admin.force_authenticate(admin_user)
 
     def _register_device(self, **kwargs):
-        """Register a new device
+        """Register a new device.
 
         Arguments:
             **kwargs: The data to pass the dummy data creation
                 method `Dummy.device_register_data`.
         Returns:
-            (dict(str, str), dict(str, str)): The tuple composed of the device
-            data that was used for the registration and the data returned by
-            the server in return.
+            (UUID, APIClient, str): The uuid of the new device as well as an
+            authentication token and the associated user with credentials.
+
         """
         data = Dummy.device_register_data(**kwargs)
         response = self.client.post(reverse(self.REGISTER_DEVICE_URL), data)
         self.assertEqual(response.status_code, status.HTTP_200_OK)
-        self.number_of_devices_created += 1
 
-        return (data, response.data)
+        uuid = response.data['uuid']
+        token = response.data['token']
+        user = APIClient()
+        user.credentials(HTTP_AUTHORIZATION='Token ' + token)
+
+        return uuid, user, token
+
+
+class DeviceTestCase(DeviceRegisterAPITestCase):
+    """Test cases for registering devices."""
+
+    def test_register(self):
+        """Test registration of devices."""
+        response = self.client.post(reverse(self.REGISTER_DEVICE_URL),
+                                    Dummy.device_register_data())
+        self.assertTrue("token" in response.data)
+        self.assertTrue("uuid" in response.data)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
+    def test_create_missing_fields(self):
+        """Test registration with missing fields."""
+        response = self.client.post(reverse(self.REGISTER_DEVICE_URL))
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+
+    def test_create_missing_board_date(self):
+        """Test registration with missing board date."""
+        data = Dummy.device_register_data()
+        data.pop('board_date')
+        response = self.client.post(reverse(self.REGISTER_DEVICE_URL), data)
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+
+    def test_create_missing_chipset(self):
+        """Test registration with missing chipset."""
+        data = Dummy.device_register_data()
+        data.pop('chipset')
+        response = self.client.post(reverse(self.REGISTER_DEVICE_URL), data)
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+
+    def test_create_invalid_board_date(self):
+        """Test registration with invalid board date."""
+        data = Dummy.device_register_data()
+        data['board_date'] = 'not_a_valid_date'
+        response = self.client.post(reverse(self.REGISTER_DEVICE_URL), data)
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+
+    def test_create_non_existent_time_board_date(self):
+        """Test registration with non existing time.
+
+        Test the resolution of a naive date-time in which the
+        Europe/Amsterdam daylight saving time transition moved the time
+        "forward". The server should not crash when receiving a naive
+        date-time which does not exist in the server timezone or locale.
+        """
+        data = Dummy.device_register_data()
+        # In 2017, the Netherlands changed from CET to CEST on March,
+        # 26 at 02:00
+        data['board_date'] = '2017-03-26 02:34:56'
+        response = self.client.post(reverse(self.REGISTER_DEVICE_URL), data)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
+    def test_create_ambiguous_time_board_date(self):
+        """Test registration with ambiguous time.
+
+        Test the resolution of a naive date-time in which the
+        Europe/Amsterdam daylight saving time transition moved the time
+        "backward". The server should not crash when receiving a naive
+        date-time that can belong to multiple timezones.
+        """
+        data = Dummy.device_register_data()
+        # In 2017, the Netherlands changed from CEST to CET on October,
+        # 29 at 03:00
+        data['board_date'] = '2017-10-29 02:34:56'
+        response = self.client.post(reverse(self.REGISTER_DEVICE_URL), data)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
 
 
 class ListDevicesTestCase(DeviceRegisterAPITestCase):
+    """Test cases for listing and deleting devices."""
 
     LIST_CREATE_URL = "api_v1_list_devices"
     RETRIEVE_URL = "api_v1_retrieve_device"
 
     def test_device_list(self):
-        request = self.admin.get(reverse(self.LIST_CREATE_URL), {})
-        self.assertIsNot(request.data['results'][1]['uuid'], '')
-        self.assertEqual(
-            len(request.data['results']), self.number_of_devices_created)
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
+        """Test registration of 2 devices."""
+        number_of_devices = 2
+        uuids = [
+            str(self._register_device()[0])
+            for _ in range(number_of_devices)
+        ]
+
+        response = self.admin.get(reverse(self.LIST_CREATE_URL), {})
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(len(response.data['results']), number_of_devices)
+        for result in response.data['results']:
+            self.assertIn(result['uuid'], uuids)
 
     def test_device_list_unauth(self):
-        request = self.client.get(reverse(self.LIST_CREATE_URL), {})
-        self.assertEqual(request.status_code, status.HTTP_401_UNAUTHORIZED)
+        """Test listing devices without authentication."""
+        response = self.client.get(reverse(self.LIST_CREATE_URL), {})
+        self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
 
     def test_retrieve_device_auth(self):
-        request = self.admin.get(
-            reverse(self.RETRIEVE_URL, args=[self.uuid]), {})
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
-        self.assertEqual(request.data['uuid'], str(self.uuid))
-        self.assertEqual(request.data['token'], self.token)
+        """Test retrieval of devices as admin user."""
+        uuid, _, token = self._register_device()
+        response = self.admin.get(reverse(self.RETRIEVE_URL, args=[uuid]), {})
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(response.data['uuid'], str(uuid))
+        self.assertEqual(response.data['token'], token)
 
     def test_retrieve_device_unauth(self):
-        request = self.client.get(
-            reverse(self.RETRIEVE_URL, args=[self.uuid]), {})
-        self.assertEqual(request.status_code, status.HTTP_401_UNAUTHORIZED)
+        """Test retrieval of devices without authentication."""
+        uuid, _, _ = self._register_device()
+        response = self.client.get(reverse(self.RETRIEVE_URL, args=[uuid]), {})
+        self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
 
     def test_delete_device_auth(self):
-        url = reverse(self.RETRIEVE_URL, args=[self.other_uuid])
-        request = self.admin.delete(url, {})
-        self.assertEqual(request.status_code, status.HTTP_204_NO_CONTENT)
-        request = self.admin.delete(url, {})
-        self.assertEqual(request.status_code, status.HTTP_404_NOT_FOUND)
+        """Test deletion of devices as admin user."""
+        uuid, _, _ = self._register_device()
+        url = reverse(self.RETRIEVE_URL, args=[uuid])
+        response = self.admin.delete(url, {})
+        self.assertEqual(response.status_code, status.HTTP_204_NO_CONTENT)
+        response = self.admin.delete(url, {})
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
 
 
 class HeartbeatListTestCase(DeviceRegisterAPITestCase):
+    """Test cases for heartbeats."""
 
     LIST_CREATE_URL = "api_v1_heartbeats"
     RETRIEVE_URL = "api_v1_heartbeat"
@@ -274,156 +292,189 @@
 
     def _retrieve_single(self, user):
         count = 5
-        requests = self._post_multiple(self.admin, self.data, count)
-        self.assertEqual(len(requests), count)
-        self.assertEqual(requests[0].status_code, status.HTTP_201_CREATED)
-        url = reverse(self.RETRIEVE_URL, args=[requests[0].data['id']])
+        response = self._post_multiple(self.admin, self.data, count)
+        self.assertEqual(len(response), count)
+        self.assertEqual(response[0].status_code, status.HTTP_201_CREATED)
+        url = reverse(self.RETRIEVE_URL, args=[response[0].data['id']])
         request = user.get(url)
         return request.status_code
 
     def _retrieve_single_by_device(self, user):
         count = 5
-        requests = self._post_multiple(self.user, self.data, count)
-        self.assertEqual(len(requests), count)
-        self.assertEqual(requests[0].status_code, status.HTTP_201_CREATED)
+        response = self._post_multiple(self.user, self.data, count)
+        self.assertEqual(len(response), count)
+        self.assertEqual(response[0].status_code, status.HTTP_201_CREATED)
         url = reverse(self.RETRIEVE_BY_UUID_URL, args=[
-            self.uuid, requests[0].data['device_local_id']])
+            self.uuid, response[0].data['device_local_id']])
         request = user.get(url)
         return request.status_code
 
     def setUp(self):
-        super(HeartbeatListTestCase, self).setUp()
+        """Set up a device and some data."""
+        super().setUp()
+        self.uuid, self.user, self.token = self._register_device()
         self.data = self._create_dummy_data(uuid=self.uuid)
 
     def test_create_no_auth(self):
-        request = self.noauth_client.post(
+        """Test creation without authentication."""
+        noauth_client = APIClient()
+        response = noauth_client.post(
             reverse(self.LIST_CREATE_URL), self.data)
-        self.assertEqual(request.status_code, status.HTTP_401_UNAUTHORIZED)
+        self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
 
     def test_create_as_admin(self):
-        request = self.admin.post(reverse(self.LIST_CREATE_URL), self.data)
-        self.assertEqual(request.status_code, status.HTTP_201_CREATED)
-        self.assertTrue(request.data['id'] > 0)
+        """Test creation as admin."""
+        response = self.admin.post(reverse(self.LIST_CREATE_URL), self.data)
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        self.assertTrue(response.data['id'] > 0)
 
     def test_create_as_admin_not_existing_device(self):
-        request = self.admin.post(
+        """Test creation of heartbeat on non-existing device."""
+        response = self.admin.post(
             reverse(self.LIST_CREATE_URL), self._create_dummy_data())
-        self.assertEqual(request.status_code, status.HTTP_404_NOT_FOUND)
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
 
     def test_create_as_uuid_owner(self):
-        request = self.user.post(
+        """Test creation as owner."""
+        response = self.user.post(
             reverse(self.LIST_CREATE_URL),
             self._create_dummy_data(uuid=self.uuid))
-        self.assertEqual(request.status_code, status.HTTP_201_CREATED)
-        self.assertEqual(request.data['id'], -1)
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        self.assertEqual(response.data['id'], -1)
 
     def test_create_as_uuid_not_owner(self):
-        request = self.user.post(
+        """Test creation as non-owner."""
+        uuid, _, _ = self._register_device()
+        response = self.user.post(
             reverse(self.LIST_CREATE_URL),
-            self._create_dummy_data(uuid=self.other_uuid))
-        self.assertEqual(request.status_code, status.HTTP_403_FORBIDDEN)
+            self._create_dummy_data(uuid=uuid))
+        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
 
     def test_list(self):
+        """Test listing of heartbeats."""
         count = 5
         self._post_multiple(self.user, self.data, count)
-        request = self.admin.get(reverse(self.LIST_CREATE_URL))
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
-        self.assertEqual(len(request.data['results']), count)
+        response = self.admin.get(reverse(self.LIST_CREATE_URL))
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(len(response.data['results']), count)
 
     def test_retrieve_single_admin(self):
+        """Test retrieval as admin."""
         self.assertEqual(
             self._retrieve_single(self.admin), status.HTTP_200_OK)
 
     def test_retrieve_single_device_owner(self):
+        """Test retrieval as device owner."""
         self.assertEqual(
             self._retrieve_single(self.user), status.HTTP_403_FORBIDDEN)
 
     def test_retrieve_single_noauth(self):
+        """Test retrieval without authentication."""
+        noauth_client = APIClient()
         self.assertEqual(
-            self._retrieve_single(self.noauth_client),
+            self._retrieve_single(noauth_client),
             status.HTTP_401_UNAUTHORIZED)
 
     def test_retrieve_single_by_device_admin(self):
+        """Test retrieval by device as admin."""
         self.assertEqual(
             self._retrieve_single_by_device(self.admin), status.HTTP_200_OK)
 
     def test_retrieve_single_by_device_device_owner(self):
+        """Test retrieval by device as owner."""
         self.assertEqual(
             self._retrieve_single_by_device(self.user),
             status.HTTP_403_FORBIDDEN)
 
     def test_retrieve_single_by_device_noauth(self):
+        """Test retrieval by device without authentication."""
+        noauth_client = APIClient()
         self.assertEqual(
-            self._retrieve_single_by_device(self.noauth_client),
+            self._retrieve_single_by_device(noauth_client),
             status.HTTP_401_UNAUTHORIZED)
 
     def test_list_by_uuid(self):
+        """Test listing of devices by UUID."""
         count = 5
+        uuid, _, _ = self._register_device()
         self._post_multiple(self.user, self.data, count)
         self._post_multiple(
-            self.admin, self._create_dummy_data(uuid=self.other_uuid), count)
+            self.admin, self._create_dummy_data(uuid=uuid), count)
         url = reverse(self.LIST_CREATE_BY_UUID_URL, args=[self.uuid])
-        request = self.admin.get(url)
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
-        self.assertEqual(len(request.data['results']), count)
+        response = self.admin.get(url)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(len(response.data['results']), count)
 
     def test_list_noauth(self):
+        """Test listing of devices without authentication."""
         count = 5
+        noauth_client = APIClient()
         self._post_multiple(self.user, self.data, count)
-        request = self.noauth_client.get(reverse(self.LIST_CREATE_URL))
-        self.assertEqual(request.status_code, status.HTTP_401_UNAUTHORIZED)
+        response = noauth_client.get(reverse(self.LIST_CREATE_URL))
+        self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
 
     def test_list_device_owner(self):
+        """Test listing as device owner."""
         count = 5
         self._post_multiple(self.user, self.data, count)
-        request = self.user.get(reverse(self.LIST_CREATE_URL))
-        self.assertEqual(request.status_code, status.HTTP_403_FORBIDDEN)
+        response = self.user.get(reverse(self.LIST_CREATE_URL))
+        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
 
     def test_no_radio_version(self):
+        """Test creation and retrieval without radio version."""
         data = self._create_dummy_data(uuid=self.uuid)
         data.pop('radio_version')
-        request = self.user.post(reverse(self.LIST_CREATE_URL), data)
-        self.assertEqual(request.status_code, status.HTTP_201_CREATED)
+        response = self.user.post(reverse(self.LIST_CREATE_URL), data)
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
         url = reverse(self.LIST_CREATE_BY_UUID_URL, args=[self.uuid])
-        request = self.admin.get(url)
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
-        self.assertEqual(len(request.data['results']), 1)
-        self.assertIsNone(request.data['results'][0]['radio_version'])
+        response = self.admin.get(url)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(len(response.data['results']), 1)
+        self.assertIsNone(response.data['results'][0]['radio_version'])
 
     def test_radio_version_field(self):
-        request = self.user.post(reverse(self.LIST_CREATE_URL), self.data)
-        self.assertEqual(request.status_code, status.HTTP_201_CREATED)
+        """Test retrieval of radio version field."""
+        response = self.user.post(reverse(self.LIST_CREATE_URL), self.data)
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
         url = reverse(self.LIST_CREATE_BY_UUID_URL, args=[self.uuid])
-        request = self.admin.get(url)
-        self.assertEqual(request.status_code, status.HTTP_200_OK)
-        self.assertEqual(len(request.data['results']), 1)
-        self.assertEqual(request.data['results'][0]['radio_version'],
-                self.data['radio_version'])
+        response = self.admin.get(url)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(len(response.data['results']), 1)
+        self.assertEqual(response.data['results'][0]['radio_version'],
+                         self.data['radio_version'])
 
     def test_send_non_existent_time(self):
-        """
-        Test the resolution of a naive date-time in which the Europe/Amsterdam daylight saving
-        time transition moved the time "forward".
+        """Test sending of heartbeat with non existent time.
+
+        Test the resolution of a naive date-time in which the
+        Europe/Amsterdam daylight saving time transition moved the time
+        "forward".
         """
         data = self._create_dummy_data(uuid=self.uuid)
-        # In 2017, the Netherlands changed from CET to CEST on March, 26 at 02:00
+        # In 2017, the Netherlands changed from CET to CEST on March,
+        # 26 at 02:00
         data['date'] = '2017-03-26 02:34:56'
-        request = self.user.post(reverse(self.LIST_CREATE_URL), data)
-        self.assertEqual(request.status_code, status.HTTP_201_CREATED)
+        response = self.user.post(reverse(self.LIST_CREATE_URL), data)
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
 
     def test_send_ambiguous_time(self):
-        """
-        Test the resolution of a naive date-time in which the Europe/Amsterdam daylight saving
-        time transition moved the time "backward".
+        """Test sending of heartbeat with ambiguous time.
+
+        Test the resolution of a naive date-time in which the
+        Europe/Amsterdam daylight saving time transition moved the time
+        "backward".
         """
         data = self._create_dummy_data(uuid=self.uuid)
-        # In 2017, the Netherlands changed from CEST to CET on October, 29 at 03:00
+        # In 2017, the Netherlands changed from CEST to CET on October,
+        # 29 at 03:00
         data['date'] = '2017-10-29 02:34:56'
-        request = self.user.post(reverse(self.LIST_CREATE_URL), data)
-        self.assertEqual(request.status_code, status.HTTP_201_CREATED)
+        response = self.user.post(reverse(self.LIST_CREATE_URL), data)
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
 
 
+# pylint: disable=too-many-ancestors
 class CrashreportListTestCase(HeartbeatListTestCase):
+    """Test cases for crash reports."""
 
     LIST_CREATE_URL = "api_v1_crashreports"
     RETRIEVE_URL = "api_v1_crashreport"
@@ -436,25 +487,50 @@
 
 
 class LogfileUploadTest(DeviceRegisterAPITestCase):
+    """Test cases for upload of log files."""
 
     LIST_CREATE_URL = "api_v1_crashreports"
     PUT_LOGFILE_URL = "api_v1_putlogfile_for_device_id"
 
-    def setUp(self):
-        super(LogfileUploadTest, self).setUp()
+    def _upload_crashreport(self, user, uuid):
+        """
+        Upload dummy crashreport data.
 
-        url = reverse(self.LIST_CREATE_URL)
-        for uuid in [self.uuid, self.other_uuid]:
-            data = Dummy.crashreport_data(uuid=uuid)
-            for _ in range(2):
-                self.user.post(url, data)
+        Args:
+            user: The user which should be used for uploading the report
+            uuid: The uuid of the device to which the report should be uploaded
 
-    def test_Logfile_upload_as_admin(self):
-        f = tempfile.NamedTemporaryFile('w+', suffix=".log", delete=True)
-        f.write(u"blihblahblub")
-        request = self.admin.post(
+        Returns: The local id of the device for which the report was uploaded.
+
+        """
+        data = Dummy.crashreport_data(uuid=uuid)
+        response = user.post(reverse(self.LIST_CREATE_URL), data)
+        self.assertEqual(status.HTTP_201_CREATED, response.status_code)
+        self.assertTrue('device_local_id' in response.data)
+        device_local_id = response.data['device_local_id']
+
+        return device_local_id
+
+    def _test_logfile_upload(self, user, uuid):
+        # Upload crashreport
+        device_local_id = self._upload_crashreport(user, uuid)
+
+        # Upload a logfile for the crashreport
+        logfile = tempfile.NamedTemporaryFile('w+', suffix=".log", delete=True)
+        logfile.write(u"blihblahblub")
+        response = user.post(
             reverse(self.PUT_LOGFILE_URL, args=[
-                self.uuid, 1, os.path.basename(f.name)
+                uuid, device_local_id, os.path.basename(logfile.name)
             ]),
-            {'file': f}, format="multipart")
-        self.assertEqual(status.HTTP_201_CREATED, request.status_code)
+            {'file': logfile}, format="multipart")
+        self.assertEqual(status.HTTP_201_CREATED, response.status_code)
+
+    def test_logfile_upload_as_user(self):
+        """Test upload of logfiles as device owner."""
+        uuid, user, _ = self._register_device()
+        self._test_logfile_upload(user, uuid)
+
+    def test_logfile_upload_as_admin(self):
+        """Test upload of logfiles as admin user."""
+        uuid, _, _ = self._register_device()
+        self._test_logfile_upload(self.admin, uuid)