diff --git a/.vscode/launch.json b/.vscode/launch.json
index f6f9287f..59444ea1 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -33,12 +33,12 @@
       "args": []
     },
     {
-      "name": "BE-DebugTest",
+      "name": "BE-DebugTestFile",
       "type": "debugpy",
       "request": "launch",
       "cwd": "${workspaceFolder}/rsconcept/backend",
       "program": "${workspaceFolder}/rsconcept/backend/manage.py",
-      "args": ["test"],
+      "args": ["test", "-k", "${fileBasenameNoExtension}"],
       "django": true
     },
     {
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/EndpointTester.py b/rsconcept/backend/apps/rsform/tests/EndpointTester.py
similarity index 80%
rename from rsconcept/backend/apps/rsform/tests/s_views/EndpointTester.py
rename to rsconcept/backend/apps/rsform/tests/EndpointTester.py
index 0c4e705f..6f1b94bf 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/EndpointTester.py
+++ b/rsconcept/backend/apps/rsform/tests/EndpointTester.py
@@ -26,7 +26,16 @@ class EndpointTester(APITestCase):
 
     def setUp(self):
         self.factory = APIRequestFactory()
-        self.user = User.objects.create(username='UserTest')
+        self.user = User.objects.create_user(
+            username='UserTest',
+            email='blank@test.com',
+            password='password'
+        )
+        self.user2 = User.objects.create_user(
+            username='UserTest2',
+            email='another@test.com',
+            password='password'
+        )
         self.client = APIClient()
         self.client.force_authenticate(user=self.user)
 
@@ -77,30 +86,6 @@ class EndpointTester(APITestCase):
         else:
             return self.client.delete(self.endpoint)
 
-    def assertOK(self, data=None, **kwargs):
-        response = self.execute(data, **kwargs)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
-
-    def assertCreated(self, data=None, **kwargs):
-        response = self.execute(data, **kwargs)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
-
-    def assertBadData(self, data=None, **kwargs):
-        response = self.execute(data, **kwargs)
-        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
-
-    def assertForbidden(self, data=None, **kwargs):
-        response = self.execute(data, **kwargs)
-        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
-
-    def assertNotModified(self, data=None, **kwargs):
-        response = self.execute(data, **kwargs)
-        self.assertEqual(response.status_code, status.HTTP_304_NOT_MODIFIED)
-
-    def assertNotFound(self, data=None, **kwargs):
-        response = self.execute(data, **kwargs)
-        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
-
     def execute(self, data=None, **kwargs):
         if self.method == 'get':
             return self.get(**kwargs)
@@ -114,6 +99,46 @@ class EndpointTester(APITestCase):
             return self.delete(data, **kwargs)
         return None
 
+    def executeOK(self, data=None, **kwargs):
+        response = self.execute(data, **kwargs)
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        return response
+
+    def executeCreated(self, data=None, **kwargs):
+        response = self.execute(data, **kwargs)
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        return response
+
+    def executeAccepted(self, data=None, **kwargs):
+        response = self.execute(data, **kwargs)
+        self.assertEqual(response.status_code, status.HTTP_202_ACCEPTED)
+        return response
+
+    def executeNoContent(self, data=None, **kwargs):
+        response = self.execute(data, **kwargs)
+        self.assertEqual(response.status_code, status.HTTP_204_NO_CONTENT)
+        return response
+
+    def executeBadData(self, data=None, **kwargs):
+        response = self.execute(data, **kwargs)
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+        return response
+
+    def executeForbidden(self, data=None, **kwargs):
+        response = self.execute(data, **kwargs)
+        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+        return response
+
+    def executeNotModified(self, data=None, **kwargs):
+        response = self.execute(data, **kwargs)
+        self.assertEqual(response.status_code, status.HTTP_304_NOT_MODIFIED)
+        return response
+
+    def executeNotFound(self, data=None, **kwargs):
+        response = self.execute(data, **kwargs)
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
+        return response
+
 
 def _resolve_url(url: str, **kwargs) -> str:
     if url == '' or len(kwargs) == 0:
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_cctext.py b/rsconcept/backend/apps/rsform/tests/s_views/t_cctext.py
index 76cef739..33c91811 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_cctext.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/t_cctext.py
@@ -1,8 +1,7 @@
 ''' Testing views '''
 from cctext import split_grams
-from rest_framework import status
 
-from .EndpointTester import EndpointTester, decl_endpoint
+from ..EndpointTester import EndpointTester, decl_endpoint
 
 
 class TestNaturalLanguageViews(EndpointTester):
@@ -15,23 +14,20 @@ class TestNaturalLanguageViews(EndpointTester):
     @decl_endpoint(endpoint='/api/cctext/parse', method='post')
     def test_parse_text(self):
         data = {'text': 'синим слонам'}
-        response = self.execute(data)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data)
         self._assert_tags(response.data['result'], 'datv,NOUN,plur,anim,masc')
 
 
     @decl_endpoint(endpoint='/api/cctext/inflect', method='post')
     def test_inflect(self):
         data = {'text': 'синий слон', 'grams': 'plur,datv'}
-        response = self.execute(data)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data)
         self.assertEqual(response.data['result'], 'синим слонам')
 
 
     @decl_endpoint(endpoint='/api/cctext/generate-lexeme', method='post')
     def test_generate_lexeme(self):
         data = {'text': 'синий слон'}
-        response = self.execute(data)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data)
         self.assertEqual(len(response.data['items']), 12)
         self.assertEqual(response.data['items'][0]['text'], 'синий слон')
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_constituents.py b/rsconcept/backend/apps/rsform/tests/s_views/t_constituents.py
index 098d2741..a19cfc49 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_constituents.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/t_constituents.py
@@ -1,9 +1,7 @@
 ''' Testing API: Constituents. '''
-from rest_framework import status
-
 from apps.rsform.models import Constituenta, CstType, RSForm
 
-from .EndpointTester import EndpointTester, decl_endpoint
+from ..EndpointTester import EndpointTester, decl_endpoint
 
 
 class TestConstituentaAPI(EndpointTester):
@@ -45,9 +43,8 @@ class TestConstituentaAPI(EndpointTester):
 
     @decl_endpoint('/api/constituents/{item}', method='get')
     def test_retrieve(self):
-        self.assertNotFound(item=self.invalid_cst)
-        response = self.execute(item=self.cst1.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.executeNotFound(item=self.invalid_cst)
+        response = self.executeOK(item=self.cst1.pk)
         self.assertEqual(response.data['alias'], self.cst1.alias)
         self.assertEqual(response.data['convention'], self.cst1.convention)
 
@@ -55,19 +52,18 @@ class TestConstituentaAPI(EndpointTester):
     @decl_endpoint('/api/constituents/{item}', method='patch')
     def test_partial_update(self):
         data = {'convention': 'tt'}
-        self.assertForbidden(data, item=self.cst2.pk)
+        self.executeForbidden(data, item=self.cst2.pk)
 
         self.logout()
-        self.assertForbidden(data, item=self.cst1.pk)
+        self.executeForbidden(data, item=self.cst1.pk)
 
         self.login()
-        response = self.execute(data, item=self.cst1.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data, item=self.cst1.pk)
         self.cst1.refresh_from_db()
         self.assertEqual(response.data['convention'], 'tt')
         self.assertEqual(self.cst1.convention, 'tt')
 
-        self.assertOK(data, item=self.cst1.pk)
+        self.executeOK(data, item=self.cst1.pk)
 
 
     @decl_endpoint('/api/constituents/{item}', method='patch')
@@ -76,8 +72,7 @@ class TestConstituentaAPI(EndpointTester):
             'term_raw': 'New term',
             'definition_raw': 'New def'
         }
-        response = self.execute(data, item=self.cst3.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data, item=self.cst3.pk)
         self.cst3.refresh_from_db()
         self.assertEqual(response.data['term_resolved'], 'New term')
         self.assertEqual(self.cst3.term_resolved, 'New term')
@@ -91,8 +86,7 @@ class TestConstituentaAPI(EndpointTester):
             'term_raw': '@{X1|nomn,sing}',
             'definition_raw': '@{X1|nomn,sing} @{X1|sing,datv}'
         }
-        response = self.execute(data, item=self.cst3.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data, item=self.cst3.pk)
         self.cst3.refresh_from_db()
         self.assertEqual(self.cst3.term_resolved, self.cst1.term_resolved)
         self.assertEqual(response.data['term_resolved'], self.cst1.term_resolved)
@@ -103,8 +97,7 @@ class TestConstituentaAPI(EndpointTester):
     @decl_endpoint('/api/constituents/{item}', method='patch')
     def test_readonly_cst_fields(self):
         data = {'alias': 'X33', 'order': 10}
-        response = self.execute(data, item=self.cst1.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data, item=self.cst1.pk)
         self.assertEqual(response.data['alias'], 'X1')
         self.assertEqual(response.data['alias'], self.cst1.alias)
         self.assertEqual(response.data['order'], self.cst1.order)
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_library.py b/rsconcept/backend/apps/rsform/tests/s_views/t_library.py
index 302cbdc3..bb99dba3 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_library.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/t_library.py
@@ -9,10 +9,9 @@ from apps.rsform.models import (
     RSForm,
     Subscription
 )
-from apps.users.models import User
 
+from ..EndpointTester import EndpointTester, decl_endpoint
 from ..testing_utils import response_contains
-from .EndpointTester import EndpointTester, decl_endpoint
 
 
 class TestLibraryViewset(EndpointTester):
@@ -20,7 +19,6 @@ class TestLibraryViewset(EndpointTester):
 
     def setUp(self):
         super().setUp()
-        self.user2 = User.objects.create(username='UserTest2')
         self.owned = LibraryItem.objects.create(
             item_type=LibraryItemType.RSFORM,
             title='Test',
@@ -46,25 +44,23 @@ class TestLibraryViewset(EndpointTester):
     @decl_endpoint('/api/library', method='post')
     def test_create(self):
         data = {'title': 'Title'}
-        response = self.post(data=data)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data)
         self.assertEqual(response.data['title'], 'Title')
         self.assertEqual(response.data['owner'], self.user.pk)
 
         self.logout()
         data = {'title': 'Title2'}
-        self.assertForbidden(data)
+        self.executeForbidden(data)
 
 
     @decl_endpoint('/api/library/{item}', method='patch')
     def test_update(self):
         data = {'id': self.unowned.pk, 'title': 'New title'}
-        self.assertNotFound(data, item=self.invalid_item)
-        self.assertForbidden(data, item=self.unowned.pk)
+        self.executeNotFound(data, item=self.invalid_item)
+        self.executeForbidden(data, item=self.unowned.pk)
 
         data = {'id': self.owned.pk, 'title': 'New title'}
-        response = self.execute(data, item=self.owned.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data, item=self.owned.pk)
         self.assertEqual(response.data['title'], 'New title')
         self.assertEqual(response.data['alias'], self.owned.alias)
 
@@ -74,22 +70,22 @@ class TestLibraryViewset(EndpointTester):
         time_update = self.owned.time_update
 
         data = {'user': self.user.pk}
-        self.assertNotFound(data, item=self.invalid_item)
-        self.assertForbidden(data, item=self.unowned.pk)
-        self.assertOK(data, item=self.owned.pk)
+        self.executeNotFound(data, item=self.invalid_item)
+        self.executeForbidden(data, item=self.unowned.pk)
+        self.executeOK(data, item=self.owned.pk)
         self.owned.refresh_from_db()
         self.assertEqual(self.owned.owner, self.user)
 
         data = {'user': self.user2.pk}
-        self.assertOK(data, item=self.owned.pk)
+        self.executeOK(data, item=self.owned.pk)
         self.owned.refresh_from_db()
         self.assertEqual(self.owned.owner, self.user2)
         self.assertEqual(self.owned.time_update, time_update)
-        self.assertForbidden(data, item=self.owned.pk)
+        self.executeForbidden(data, item=self.owned.pk)
 
         self.toggle_admin(True)
         data = {'user': self.user.pk}
-        self.assertOK(data, item=self.owned.pk)
+        self.executeOK(data, item=self.owned.pk)
         self.owned.refresh_from_db()
         self.assertEqual(self.owned.owner, self.user)
 
@@ -98,22 +94,22 @@ class TestLibraryViewset(EndpointTester):
         time_update = self.owned.time_update
 
         data = {'user': self.invalid_user}
-        self.assertBadData(data, item=self.owned.pk)
+        self.executeBadData(data, item=self.owned.pk)
 
         data = {'user': self.user.pk}
-        self.assertNotFound(data, item=self.invalid_item)
-        self.assertForbidden(data, item=self.unowned.pk)
+        self.executeNotFound(data, item=self.invalid_item)
+        self.executeForbidden(data, item=self.unowned.pk)
 
-        self.assertOK(data, item=self.owned.pk)
+        self.executeOK(data, item=self.owned.pk)
         self.owned.refresh_from_db()
         self.assertEqual(self.owned.time_update, time_update)
         self.assertEqual(self.owned.editors(), [self.user])
 
-        self.assertOK(data)
+        self.executeOK(data)
         self.assertEqual(self.owned.editors(), [self.user])
 
         data = {'user': self.user2.pk}
-        self.assertOK(data)
+        self.executeOK(data)
         self.assertEqual(set(self.owned.editors()), set([self.user, self.user2]))
 
 
@@ -122,25 +118,25 @@ class TestLibraryViewset(EndpointTester):
         time_update = self.owned.time_update
 
         data = {'user': self.invalid_user}
-        self.assertBadData(data, item=self.owned.pk)
+        self.executeBadData(data, item=self.owned.pk)
 
         data = {'user': self.user.pk}
-        self.assertNotFound(data, item=self.invalid_item)
-        self.assertForbidden(data, item=self.unowned.pk)
+        self.executeNotFound(data, item=self.invalid_item)
+        self.executeForbidden(data, item=self.unowned.pk)
 
-        self.assertOK(data, item=self.owned.pk)
+        self.executeOK(data, item=self.owned.pk)
         self.owned.refresh_from_db()
         self.assertEqual(self.owned.time_update, time_update)
         self.assertEqual(self.owned.editors(), [])
 
         Editor.add(item=self.owned, user=self.user)
-        self.assertOK(data)
+        self.executeOK(data)
         self.assertEqual(self.owned.editors(), [])
 
         Editor.add(item=self.owned, user=self.user)
         Editor.add(item=self.owned, user=self.user2)
         data = {'user': self.user2.pk}
-        self.assertOK(data)
+        self.executeOK(data)
         self.assertEqual(self.owned.editors(), [self.user])
 
 
@@ -149,30 +145,30 @@ class TestLibraryViewset(EndpointTester):
         time_update = self.owned.time_update
 
         data = {'users': [self.invalid_user]}
-        self.assertBadData(data, item=self.owned.pk)
+        self.executeBadData(data, item=self.owned.pk)
 
         data = {'users': [self.user.pk]}
-        self.assertNotFound(data, item=self.invalid_item)
-        self.assertForbidden(data, item=self.unowned.pk)
+        self.executeNotFound(data, item=self.invalid_item)
+        self.executeForbidden(data, item=self.unowned.pk)
 
-        self.assertOK(data, item=self.owned.pk)
+        self.executeOK(data, item=self.owned.pk)
         self.owned.refresh_from_db()
         self.assertEqual(self.owned.time_update, time_update)
         self.assertEqual(self.owned.editors(), [self.user])
 
-        self.assertOK(data)
+        self.executeOK(data)
         self.assertEqual(self.owned.editors(), [self.user])
 
         data = {'users': [self.user2.pk]}
-        self.assertOK(data)
+        self.executeOK(data)
         self.assertEqual(self.owned.editors(), [self.user2])
 
         data = {'users': []}
-        self.assertOK(data)
+        self.executeOK(data)
         self.assertEqual(self.owned.editors(), [])
 
         data = {'users': [self.user2.pk, self.user.pk]}
-        self.assertOK(data)
+        self.executeOK(data)
         self.assertEqual(set(self.owned.editors()), set([self.user2, self.user]))
 
 
@@ -181,7 +177,7 @@ class TestLibraryViewset(EndpointTester):
         response = self.execute(item=self.owned.pk)
         self.assertTrue(response.status_code in [status.HTTP_202_ACCEPTED, status.HTTP_204_NO_CONTENT])
 
-        self.assertForbidden(item=self.unowned.pk)
+        self.executeForbidden(item=self.unowned.pk)
         self.toggle_admin(True)
         response = self.execute(item=self.unowned.pk)
         self.assertTrue(response.status_code in [status.HTTP_202_ACCEPTED, status.HTTP_204_NO_CONTENT])
@@ -189,15 +185,13 @@ class TestLibraryViewset(EndpointTester):
 
     @decl_endpoint('/api/library/active', method='get')
     def test_retrieve_common(self):
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertTrue(response_contains(response, self.common))
         self.assertFalse(response_contains(response, self.unowned))
         self.assertTrue(response_contains(response, self.owned))
 
         self.logout()
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertTrue(response_contains(response, self.common))
         self.assertFalse(response_contains(response, self.unowned))
         self.assertFalse(response_contains(response, self.owned))
@@ -206,47 +200,42 @@ class TestLibraryViewset(EndpointTester):
     @decl_endpoint('/api/library/all', method='get')
     def test_retrieve_all(self):
         self.toggle_admin(False)
-        self.assertForbidden()
+        self.executeForbidden()
         self.toggle_admin(True)
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertTrue(response_contains(response, self.common))
         self.assertTrue(response_contains(response, self.unowned))
         self.assertTrue(response_contains(response, self.owned))
 
         self.logout()
-        self.assertForbidden()
+        self.executeForbidden()
 
 
     @decl_endpoint('/api/library/active', method='get')
     def test_retrieve_subscribed(self):
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertFalse(response_contains(response, self.unowned))
 
         Subscription.subscribe(user=self.user, item=self.unowned)
         Subscription.subscribe(user=self.user2, item=self.unowned)
         Subscription.subscribe(user=self.user2, item=self.owned)
 
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertTrue(response_contains(response, self.unowned))
         self.assertEqual(len(response.data), 3)
 
 
     @decl_endpoint('/api/library/{item}/subscribe', method='post')
     def test_subscriptions(self):
-        self.assertNotFound(item=self.invalid_item)
+        self.executeNotFound(item=self.invalid_item)
         response = self.client.delete(f'/api/library/{self.unowned.pk}/unsubscribe')
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertFalse(self.user in self.unowned.subscribers())
 
-        response = self.execute(item=self.unowned.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(item=self.unowned.pk)
         self.assertTrue(self.user in self.unowned.subscribers())
 
-        response = self.execute(item=self.unowned.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(item=self.unowned.pk)
         self.assertTrue(self.user in self.unowned.subscribers())
 
         response = self.client.delete(f'/api/library/{self.unowned.pk}/unsubscribe')
@@ -256,15 +245,13 @@ class TestLibraryViewset(EndpointTester):
 
     @decl_endpoint('/api/library/templates', method='get')
     def test_retrieve_templates(self):
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertFalse(response_contains(response, self.common))
         self.assertFalse(response_contains(response, self.unowned))
         self.assertFalse(response_contains(response, self.owned))
 
         LibraryTemplate.objects.create(lib_source=self.unowned)
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertFalse(response_contains(response, self.common))
         self.assertTrue(response_contains(response, self.unowned))
         self.assertFalse(response_contains(response, self.owned))
@@ -284,12 +271,11 @@ class TestLibraryViewset(EndpointTester):
         )
 
         data = {'title': 'Title1337'}
-        self.assertNotFound(data, item=self.invalid_item)
-        self.assertCreated(data, item=self.unowned.pk)
+        self.executeNotFound(data, item=self.invalid_item)
+        self.executeCreated(data, item=self.unowned.pk)
 
         data = {'title': 'Title1338'}
-        response = self.execute(data, item=self.owned.pk)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data, item=self.owned.pk)
         self.assertEqual(response.data['title'], data['title'])
         self.assertEqual(len(response.data['items']), 2)
         self.assertEqual(response.data['items'][0]['alias'], x12.alias)
@@ -299,14 +285,12 @@ class TestLibraryViewset(EndpointTester):
         self.assertEqual(response.data['items'][1]['term_resolved'], d2.term_resolved)
 
         data = {'title': 'Title1340', 'items': []}
-        response = self.execute(data, item=self.owned.pk)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data, item=self.owned.pk)
         self.assertEqual(response.data['title'], data['title'])
         self.assertEqual(len(response.data['items']), 0)
 
         data = {'title': 'Title1341', 'items': [x12.pk]}
-        response = self.execute(data, item=self.owned.pk)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data, item=self.owned.pk)
         self.assertEqual(response.data['title'], data['title'])
         self.assertEqual(len(response.data['items']), 1)
         self.assertEqual(response.data['items'][0]['alias'], x12.alias)
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_operations.py b/rsconcept/backend/apps/rsform/tests/s_views/t_operations.py
index 33faab82..0cd9867f 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_operations.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/t_operations.py
@@ -1,9 +1,7 @@
 ''' Testing API: Operations. '''
-from rest_framework import status
-
 from apps.rsform.models import Constituenta, CstType, RSForm
 
-from .EndpointTester import EndpointTester, decl_endpoint
+from ..EndpointTester import EndpointTester, decl_endpoint
 
 
 class TestInlineSynthesis(EndpointTester):
@@ -26,20 +24,20 @@ class TestInlineSynthesis(EndpointTester):
             'items': [],
             'substitutions': []
         }
-        self.assertForbidden(data)
+        self.executeForbidden(data)
 
         data['receiver'] = invalid_id
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         data['receiver'] = self.schema1.item.pk
         data['source'] = invalid_id
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         data['source'] = self.schema1.item.pk
-        self.assertOK(data)
+        self.executeOK(data)
 
         data['items'] = [invalid_id]
-        self.assertBadData(data)
+        self.executeBadData(data)
 
 
     def test_inline_synthesis(self):
@@ -70,8 +68,7 @@ class TestInlineSynthesis(EndpointTester):
                 }
             ]
         }
-        response = self.execute(data)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data)
         result = {item['alias']: item for item in response.data['items']}
         self.assertEqual(len(result), 6)
         self.assertEqual(result['X2']['term_raw'], ks1_x2.term_raw)
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_rsforms.py b/rsconcept/backend/apps/rsform/tests/s_views/t_rsforms.py
index e0a10b16..3ad506e3 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_rsforms.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/t_rsforms.py
@@ -8,8 +8,8 @@ from rest_framework import status
 
 from apps.rsform.models import Constituenta, CstType, LibraryItem, LibraryItemType, RSForm
 
+from ..EndpointTester import EndpointTester, decl_endpoint
 from ..testing_utils import response_contains
-from .EndpointTester import EndpointTester, decl_endpoint
 
 
 class TestRSFormViewset(EndpointTester):
@@ -39,8 +39,7 @@ class TestRSFormViewset(EndpointTester):
     @decl_endpoint('/api/rsforms/create-detailed', method='post')
     def test_create_rsform_json(self):
         data = {'title': 'Test123', 'comment': '123', 'alias': 'ks1'}
-        response = self.execute(data)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data)
         self.assertEqual(response.data['owner'], self.user.pk)
         self.assertEqual(response.data['title'], 'Test123')
         self.assertEqual(response.data['alias'], 'ks1')
@@ -53,8 +52,7 @@ class TestRSFormViewset(EndpointTester):
             item_type=LibraryItemType.OPERATIONS_SCHEMA,
             title='Test3'
         )
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertFalse(response_contains(response, non_schema))
         self.assertTrue(response_contains(response, self.unowned.item))
         self.assertTrue(response_contains(response, self.schema.item))
@@ -70,7 +68,7 @@ class TestRSFormViewset(EndpointTester):
     def test_contents(self):
         schema = RSForm.create(title='Title1')
         schema.insert_new('X1')
-        self.assertOK(item=schema.item.pk)
+        self.executeOK(item=schema.item.pk)
 
 
     @decl_endpoint('/api/rsforms/{item}/details', method='get')
@@ -87,8 +85,7 @@ class TestRSFormViewset(EndpointTester):
             term_resolved='люди'
         )
 
-        response = self.execute(item=schema.item.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(item=schema.item.pk)
         self.assertEqual(response.data['title'], 'Test')
         self.assertEqual(len(response.data['items']), 2)
         self.assertEqual(response.data['items'][0]['id'], x1.pk)
@@ -107,15 +104,14 @@ class TestRSFormViewset(EndpointTester):
         schema = RSForm.create(title='Test')
         schema.insert_new('X1')
         data = {'expression': 'X1=X1'}
-        response = self.execute(data, item=schema.item.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data, item=schema.item.pk)
         self.assertEqual(response.data['parseResult'], True)
         self.assertEqual(response.data['syntax'], 'math')
         self.assertEqual(response.data['astText'], '[=[X1][X1]]')
         self.assertEqual(response.data['typification'], 'LOGIC')
         self.assertEqual(response.data['valueClass'], 'value')
 
-        self.assertOK(data, item=self.unowned_id)
+        self.executeOK(data, item=self.unowned_id)
 
 
     @decl_endpoint('/api/rsforms/{item}/resolve', method='post')
@@ -127,8 +123,7 @@ class TestRSFormViewset(EndpointTester):
         )
 
         data = {'text': '@{1|редкий} @{X1|plur,datv}'}
-        response = self.execute(data, item=schema.item.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data, item=schema.item.pk)
         self.assertEqual(response.data['input'], '@{1|редкий} @{X1|plur,datv}')
         self.assertEqual(response.data['output'], 'редким синим слонам')
         self.assertEqual(len(response.data['refs']), 2)
@@ -165,8 +160,7 @@ class TestRSFormViewset(EndpointTester):
     def test_export_trs(self):
         schema = RSForm.create(title='Test')
         schema.insert_new('X1')
-        response = self.execute(item=schema.item.pk)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(item=schema.item.pk)
         self.assertEqual(response.headers['Content-Disposition'], 'attachment; filename=Schema.trs')
         with io.BytesIO(response.content) as stream:
             with ZipFile(stream, 'r') as zipped_file:
@@ -177,13 +171,12 @@ class TestRSFormViewset(EndpointTester):
     @decl_endpoint('/api/rsforms/{item}/cst-create', method='post')
     def test_create_constituenta(self):
         data = {'alias': 'X3', 'cst_type': CstType.BASE}
-        self.assertForbidden(data, item=self.unowned_id)
+        self.executeForbidden(data, item=self.unowned_id)
 
         self.schema.insert_new('X1')
         x2 = self.schema.insert_new('X2')
 
-        response = self.execute(data, item=self.schema_id)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data, item=self.schema_id)
         self.assertEqual(response.data['new_cst']['alias'], 'X3')
         x3 = Constituenta.objects.get(alias=response.data['new_cst']['alias'])
         self.assertEqual(x3.order, 3)
@@ -195,8 +188,7 @@ class TestRSFormViewset(EndpointTester):
             'term_raw': 'test',
             'term_forms': [{'text': 'form1', 'tags': 'sing,datv'}]
         }
-        response = self.execute(data, item=self.schema_id)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data, item=self.schema_id)
         self.assertEqual(response.data['new_cst']['alias'], data['alias'])
         x4 = Constituenta.objects.get(alias=response.data['new_cst']['alias'])
         self.assertEqual(x4.order, 3)
@@ -223,14 +215,14 @@ class TestRSFormViewset(EndpointTester):
         )
 
         data = {'target': x2_2.pk, 'alias': 'D2', 'cst_type': CstType.TERM}
-        self.assertForbidden(data, item=self.unowned_id)
-        self.assertBadData(data, item=self.schema_id)
+        self.executeForbidden(data, item=self.unowned_id)
+        self.executeBadData(data, item=self.schema_id)
 
         data = {'target': x1.pk, 'alias': x1.alias, 'cst_type': CstType.TERM}
-        self.assertBadData(data, item=self.schema_id)
+        self.executeBadData(data, item=self.schema_id)
 
         data = {'target': x1.pk, 'alias': x3.alias}
-        self.assertBadData(data, item=self.schema_id)
+        self.executeBadData(data, item=self.schema_id)
 
         d1 = self.schema.insert_new(
             alias='D1',
@@ -242,8 +234,7 @@ class TestRSFormViewset(EndpointTester):
         self.assertEqual(x1.cst_type, CstType.BASE)
 
         data = {'target': x1.pk, 'alias': 'D2', 'cst_type': CstType.TERM}
-        response = self.execute(data, item=self.schema_id)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data, item=self.schema_id)
         self.assertEqual(response.data['new_cst']['alias'], 'D2')
         self.assertEqual(response.data['new_cst']['cst_type'], CstType.TERM)
         d1.refresh_from_db()
@@ -270,14 +261,14 @@ class TestRSFormViewset(EndpointTester):
         unowned = self.unowned.insert_new('X2')
 
         data = {'substitutions': [{'original': x1.pk, 'substitution': unowned.pk, 'transfer_term': True}]}
-        self.assertForbidden(data, item=self.unowned_id)
-        self.assertBadData(data, item=self.schema_id)
+        self.executeForbidden(data, item=self.unowned_id)
+        self.executeBadData(data, item=self.schema_id)
 
         data = {'substitutions': [{'original': unowned.pk, 'substitution': x1.pk, 'transfer_term': True}]}
-        self.assertBadData(data, item=self.schema_id)
+        self.executeBadData(data, item=self.schema_id)
 
         data = {'substitutions': [{'original': x1.pk, 'substitution': x1.pk, 'transfer_term': True}]}
-        self.assertBadData(data, item=self.schema_id)
+        self.executeBadData(data, item=self.schema_id)
 
         d1 = self.schema.insert_new(
             alias='D1',
@@ -285,9 +276,7 @@ class TestRSFormViewset(EndpointTester):
             definition_formal='X1'
         )
         data = {'substitutions': [{'original': x1.pk, 'substitution': x2.pk, 'transfer_term': True}]}
-        response = self.execute(data, item=self.schema_id)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
-
+        response = self.executeOK(data, item=self.schema_id)
         d1.refresh_from_db()
         x2.refresh_from_db()
         self.assertEqual(x2.term_raw, 'Test1')
@@ -307,7 +296,7 @@ class TestRSFormViewset(EndpointTester):
         )
 
         data = {'substitutions': []}
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         data = {'substitutions': [
             {
@@ -321,7 +310,7 @@ class TestRSFormViewset(EndpointTester):
                 'transfer_term': True
             }
         ]}
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         data = {'substitutions': [
             {
@@ -335,9 +324,7 @@ class TestRSFormViewset(EndpointTester):
                 'transfer_term': True
             }
         ]}
-        response = self.execute(data, item=self.schema_id)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
-
+        response = self.executeOK(data, item=self.schema_id)
         d3.refresh_from_db()
         self.assertEqual(d3.definition_formal, r'D1 \ D2')
 
@@ -352,8 +339,7 @@ class TestRSFormViewset(EndpointTester):
             'definition_formal': '3',
             'definition_raw': '4'
         }
-        response = self.execute(data, item=self.schema_id)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data, item=self.schema_id)
         self.assertEqual(response.data['new_cst']['alias'], 'X3')
         self.assertEqual(response.data['new_cst']['cst_type'], CstType.BASE)
         self.assertEqual(response.data['new_cst']['convention'], '1')
@@ -369,16 +355,15 @@ class TestRSFormViewset(EndpointTester):
         self.set_params(item=self.schema_id)
 
         data = {'items': [1337]}
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         x1 = self.schema.insert_new('X1')
         x2 = self.schema.insert_new('X2')
 
         data = {'items': [x1.pk]}
-        response = self.execute(data)
+        response = self.executeOK(data)
         x2.refresh_from_db()
         self.schema.item.refresh_from_db()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertEqual(len(response.data['items']), 1)
         self.assertEqual(self.schema.constituents().count(), 1)
         self.assertEqual(x2.alias, 'X2')
@@ -386,7 +371,7 @@ class TestRSFormViewset(EndpointTester):
 
         x3 = self.unowned.insert_new('X1')
         data = {'items': [x3.pk]}
-        self.assertBadData(data, item=self.schema_id)
+        self.executeBadData(data, item=self.schema_id)
 
 
     @decl_endpoint('/api/rsforms/{item}/cst-moveto', method='patch')
@@ -394,42 +379,39 @@ class TestRSFormViewset(EndpointTester):
         self.set_params(item=self.schema_id)
 
         data = {'items': [1337], 'move_to': 1}
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         x1 = self.schema.insert_new('X1')
         x2 = self.schema.insert_new('X2')
 
         data = {'items': [x2.pk], 'move_to': 1}
-        response = self.execute(data)
+        response = self.executeOK(data)
         x1.refresh_from_db()
         x2.refresh_from_db()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertEqual(response.data['id'], self.schema_id)
         self.assertEqual(x1.order, 2)
         self.assertEqual(x2.order, 1)
 
         x3 = self.unowned.insert_new('X1')
         data = {'items': [x3.pk], 'move_to': 1}
-        self.assertBadData(data)
+        self.executeBadData(data)
 
 
     @decl_endpoint('/api/rsforms/{item}/reset-aliases', method='patch')
     def test_reset_aliases(self):
         self.set_params(item=self.schema_id)
 
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertEqual(response.data['id'], self.schema_id)
 
         x2 = self.schema.insert_new('X2')
         x1 = self.schema.insert_new('X1')
         d11 = self.schema.insert_new('D11')
 
-        response = self.execute()
+        response = self.executeOK()
         x1.refresh_from_db()
         x2.refresh_from_db()
         d11.refresh_from_db()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertEqual(x2.order, 1)
         self.assertEqual(x2.alias, 'X1')
         self.assertEqual(x1.order, 2)
@@ -437,7 +419,7 @@ class TestRSFormViewset(EndpointTester):
         self.assertEqual(d11.order, 3)
         self.assertEqual(d11.alias, 'D1')
 
-        self.assertOK()
+        self.executeOK()
 
 
     @decl_endpoint('/api/rsforms/{item}/load-trs', method='patch')
@@ -484,13 +466,12 @@ class TestRSFormViewset(EndpointTester):
         )
         invalid_id = f1.pk + 1337
 
-        self.assertBadData({'target': invalid_id})
-        self.assertBadData({'target': x1.pk})
-        self.assertBadData({'target': s2.pk})
+        self.executeBadData({'target': invalid_id})
+        self.executeBadData({'target': x1.pk})
+        self.executeBadData({'target': s2.pk})
 
         # Testing simple structure
-        response = self.execute({'target': s1.pk})
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data={'target': s1.pk})
         result = response.data['schema']
         items = [item for item in result['items'] if item['id'] in response.data['cst_list']]
         self.assertEqual(len(items), 2)
@@ -501,8 +482,7 @@ class TestRSFormViewset(EndpointTester):
 
         # Testing complex structure
         s3.refresh_from_db()
-        response = self.execute({'target': s3.pk})
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data={'target': s3.pk})
         result = response.data['schema']
         items = [item for item in result['items'] if item['id'] in response.data['cst_list']]
         self.assertEqual(len(items), 8)
@@ -511,8 +491,7 @@ class TestRSFormViewset(EndpointTester):
 
         # Testing function
         f1.refresh_from_db()
-        response = self.execute({'target': f1.pk})
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data={'target': f1.pk})
         result = response.data['schema']
         items = [item for item in result['items'] if item['id'] in response.data['cst_list']]
         self.assertEqual(len(items), 2)
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_rslang.py b/rsconcept/backend/apps/rsform/tests/s_views/t_rslang.py
index 185586b2..910e852e 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_rslang.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/t_rslang.py
@@ -1,44 +1,37 @@
 ''' Testing views '''
-from rest_framework import status
-from rest_framework.exceptions import ErrorDetail
-
-from .EndpointTester import EndpointTester, decl_endpoint
+from ..EndpointTester import EndpointTester, decl_endpoint
 
 
 class TestRSLanguageViews(EndpointTester):
     ''' Test RS language endpoints. '''
 
-
     @decl_endpoint('/api/rslang/to-ascii', method='post')
     def test_convert_to_ascii(self):
         data = {'data': '1=1'}
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         data = {'expression': '1=1'}
-        response = self.execute(data)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data)
         self.assertEqual(response.data['result'], r'1 \eq 1')
 
 
     @decl_endpoint('/api/rslang/to-math', method='post')
     def test_convert_to_math(self):
         data = {'data': r'1 \eq 1'}
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         data = {'expression': r'1 \eq 1'}
-        response = self.execute(data)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data)
         self.assertEqual(response.data['result'], r'1=1')
 
 
     @decl_endpoint('/api/rslang/parse-expression', method='post')
     def test_parse_expression(self):
         data = {'data': r'1=1'}
-        self.assertBadData(data)
+        self.executeBadData(data)
 
         data = {'expression': r'1=1'}
-        response = self.execute(data)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(data)
         self.assertEqual(response.data['parseResult'], True)
         self.assertEqual(response.data['syntax'], 'math')
         self.assertEqual(response.data['astText'], '[=[1][1]]')
diff --git a/rsconcept/backend/apps/rsform/tests/s_views/t_versions.py b/rsconcept/backend/apps/rsform/tests/s_views/t_versions.py
index 62fcef7a..d2b273a7 100644
--- a/rsconcept/backend/apps/rsform/tests/s_views/t_versions.py
+++ b/rsconcept/backend/apps/rsform/tests/s_views/t_versions.py
@@ -8,7 +8,7 @@ from rest_framework import status
 
 from apps.rsform.models import Constituenta, RSForm
 
-from .EndpointTester import EndpointTester, decl_endpoint
+from ..EndpointTester import EndpointTester, decl_endpoint
 
 
 class TestVersionViews(EndpointTester):
@@ -31,12 +31,11 @@ class TestVersionViews(EndpointTester):
         invalid_id = 1338
         data = {'version': '1.0.0', 'description': 'test'}
 
-        self.assertNotFound(data, schema=invalid_id)
-        self.assertForbidden(data, schema=self.unowned.pk)
-        self.assertBadData(invalid_data, schema=self.owned.pk)
+        self.executeNotFound(data, schema=invalid_id)
+        self.executeForbidden(data, schema=self.unowned.pk)
+        self.executeBadData(invalid_data, schema=self.owned.pk)
 
-        response = self.execute(data, schema=self.owned.pk)
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        response = self.executeCreated(data, schema=self.owned.pk)
         self.assertTrue('version' in response.data)
         self.assertTrue('schema' in response.data)
         self.assertTrue(response.data['version'] in [v['id'] for v in response.data['schema']['versions']])
@@ -47,18 +46,17 @@ class TestVersionViews(EndpointTester):
         version_id = self._create_version({'version': '1.0.0', 'description': 'test'})
         invalid_id = version_id + 1337
 
-        self.assertNotFound(schema=invalid_id, version=invalid_id)
-        self.assertNotFound(schema=self.owned.pk, version=invalid_id)
-        self.assertNotFound(schema=invalid_id, version=version_id)
-        self.assertNotFound(schema=self.unowned.pk, version=version_id)
+        self.executeNotFound(schema=invalid_id, version=invalid_id)
+        self.executeNotFound(schema=self.owned.pk, version=invalid_id)
+        self.executeNotFound(schema=invalid_id, version=version_id)
+        self.executeNotFound(schema=self.unowned.pk, version=version_id)
 
         self.owned.alias = 'NewName'
         self.owned.save()
         self.x1.alias = 'X33'
         self.x1.save()
 
-        response = self.execute(schema=self.owned.pk, version=version_id)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(schema=self.owned.pk, version=version_id)
         self.assertNotEqual(response.data['alias'], self.owned.alias)
         self.assertNotEqual(response.data['items'][0]['alias'], self.x1.alias)
         self.assertEqual(response.data['version'], version_id)
@@ -70,26 +68,25 @@ class TestVersionViews(EndpointTester):
         version_id = self._create_version(data)
         invalid_id = version_id + 1337
 
-        self.assertNotFound(version=invalid_id)
+        self.executeNotFound(version=invalid_id)
 
         self.set_params(version=version_id)
         self.logout()
-        response = self.execute()
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK()
         self.assertEqual(response.data['version'], data['version'])
         self.assertEqual(response.data['description'], data['description'])
         self.assertEqual(response.data['item'], self.owned.pk)
 
         data = {'version': '1.2.0', 'description': 'test1'}
         self.method = 'patch'
-        self.assertForbidden(data)
+        self.executeForbidden(data)
 
         self.method = 'delete'
-        self.assertForbidden()
+        self.executeForbidden()
 
         self.client.force_authenticate(user=self.user)
         self.method = 'patch'
-        self.assertOK(data)
+        self.executeOK(data)
         response = self.get()
         self.assertEqual(response.data['version'], data['version'])
         self.assertEqual(response.data['description'], data['description'])
@@ -113,8 +110,7 @@ class TestVersionViews(EndpointTester):
         a1.definition_formal = 'X1=X2'
         a1.save()
 
-        response = self.get(schema=self.owned.pk, version=version_id)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(schema=self.owned.pk, version=version_id)
         loaded_a1 = response.data['items'][1]
         self.assertEqual(loaded_a1['definition_formal'], 'X1=X1')
         self.assertEqual(loaded_a1['parse']['status'], 'verified')
@@ -123,11 +119,10 @@ class TestVersionViews(EndpointTester):
     @decl_endpoint('/api/versions/{version}/export-file', method='get')
     def test_export_version(self):
         invalid_id = 1338
-        self.assertNotFound(version=invalid_id)
+        self.executeNotFound(version=invalid_id)
 
         version_id = self._create_version({'version': '1.0.0', 'description': 'test'})
-        response = self.get(version=version_id)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(version=version_id)
         self.assertEqual(
             response.headers['Content-Disposition'],
             f'attachment; filename={self.owned.alias}.trs'
@@ -156,10 +151,9 @@ class TestVersionViews(EndpointTester):
         x3.order = 1
         x3.save()
 
-        self.assertNotFound(version=invalid_id)
+        self.executeNotFound(version=invalid_id)
 
-        response = self.execute(version=version_id)
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.executeOK(version=version_id)
         x1.refresh_from_db()
         x2.refresh_from_db()
         self.assertEqual(len(response.data['items']), 3)
diff --git a/rsconcept/backend/apps/users/messages.py b/rsconcept/backend/apps/users/messages.py
index a99495fb..a7ea4f94 100644
--- a/rsconcept/backend/apps/users/messages.py
+++ b/rsconcept/backend/apps/users/messages.py
@@ -8,3 +8,7 @@ def passwordAuthFailed():
 
 def passwordsNotMatch():
     return 'Введенные пароли не совпадают'
+
+
+def emailAlreadyTaken():
+    return 'Пользователь с данным email уже существует'
diff --git a/rsconcept/backend/apps/users/serializers.py b/rsconcept/backend/apps/users/serializers.py
index 984804f7..519f74d6 100644
--- a/rsconcept/backend/apps/users/serializers.py
+++ b/rsconcept/backend/apps/users/serializers.py
@@ -1,4 +1,6 @@
 ''' Serializers: User profile and Authorization. '''
+from urllib import request
+
 from django.contrib.auth import authenticate
 from django.contrib.auth.password_validation import validate_password
 from rest_framework import serializers
@@ -99,6 +101,17 @@ class UserSerializer(serializers.ModelSerializer):
             'last_name',
         ]
 
+    def validate(self, attrs):
+        attrs = super().validate(attrs)
+        if 'email' in attrs:
+            maybe_user = models.User.objects.filter(email=attrs['email'])
+            if maybe_user.exists():
+                if maybe_user.count() > 1 or maybe_user.first().pk != self.context['request'].user.pk:
+                    raise serializers.ValidationError({
+                        'email': msg.emailAlreadyTaken()
+                    })
+        return attrs
+
 
 class ChangePasswordSerializer(serializers.Serializer):
     ''' Serializer: Change password. '''
@@ -130,11 +143,17 @@ class SignupSerializer(serializers.ModelSerializer):
             raise serializers.ValidationError({
                 'password': msg.passwordsNotMatch()
             })
+        if models.User.objects.filter(email=attrs['email']).exists():
+            raise serializers.ValidationError({
+                'email': msg.emailAlreadyTaken()
+            })
         return attrs
 
     def create(self, validated_data):
         user = models.User.objects.create_user(
-            validated_data['username'],  validated_data['email'],  validated_data['password']
+            username=validated_data['username'],
+            email=validated_data['email'],
+            password=validated_data['password']
         )
         user.first_name = validated_data['first_name']
         user.last_name = validated_data['last_name']
diff --git a/rsconcept/backend/apps/users/tests/t_views.py b/rsconcept/backend/apps/users/tests/t_views.py
index 57a4a738..cc7f51b2 100644
--- a/rsconcept/backend/apps/users/tests/t_views.py
+++ b/rsconcept/backend/apps/users/tests/t_views.py
@@ -1,195 +1,186 @@
-''' Testing views '''
+''' Testing API: users. '''
 from rest_framework.test import APIClient, APITestCase
 
-from apps.rsform.models import LibraryItem, LibraryItemType
+from apps.rsform.tests.EndpointTester import EndpointTester, decl_endpoint
 from apps.users.models import User
 
 
-class TestUserAPIViews(APITestCase):
+class TestUserAPIViews(EndpointTester):
+    ''' Testing Authentication views. '''
+
     def setUp(self):
-        self.username = 'UserTest'
-        self.email = 'test@test.com'
-        self.password = 'password'
-        self.user = User.objects.create_user(
-            self.username, self.email, self.password
-        )
-        self.client = APIClient()
+        super().setUp()
 
+
+    @decl_endpoint('/users/api/login', method='post')
     def test_login(self):
-        data = {'username': self.username, 'password': self.password}
-        response = self.client.post(
-            '/users/api/login',
-            data=data, format='json'
-        )
-        self.assertEqual(response.status_code, 202)
+        self.logout()
+        data = {'username': self.user.username, 'password': 'invalid'}
+        self.executeBadData(data)
 
+        data = {'username': self.user.username, 'password': 'password'}
+        self.executeAccepted(data)
+        self.executeAccepted(data)
+
+
+    @decl_endpoint('/users/api/logout', method='post')
     def test_logout(self):
-        self.assertEqual(self.client.post('/users/api/logout').status_code, 403)
+        self.logout()
+        self.executeForbidden()
 
-        self.client.force_login(user=self.user)
-        self.assertEqual(self.client.get('/users/api/logout').status_code, 405)
-        self.assertEqual(self.client.post('/users/api/logout').status_code, 204)
+        self.login()
+        self.executeNoContent()
+        self.executeNoContent()
 
-        self.assertEqual(self.client.post('/users/api/logout').status_code, 403)
 
+    @decl_endpoint('/users/api/auth', method='get')
     def test_auth(self):
-        LibraryItem.objects.create(item_type=LibraryItemType.RSFORM, title='T1')
-        item = LibraryItem.objects.create(
-            item_type=LibraryItemType.RSFORM,
-            title='Test',
-            alias='T1',
-            is_common=True,
-            owner=self.user
-        )
-        response = self.client.get('/users/api/auth')
-        self.assertEqual(response.status_code, 200)
+        response = self.executeOK()
+        self.assertEqual(response.data['id'], self.user.pk)
+        self.assertEqual(response.data['username'], self.user.username)
+        self.assertEqual(response.data['is_staff'], self.user.is_staff)
+        self.assertEqual(response.data['subscriptions'], [])
+
+        self.logout()
+        response = self.executeOK()
         self.assertEqual(response.data['id'], None)
         self.assertEqual(response.data['username'], '')
         self.assertEqual(response.data['is_staff'], False)
         self.assertEqual(response.data['subscriptions'], [])
 
-        self.client.force_login(self.user)
-        response = self.client.get('/users/api/auth')
-        self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.data['id'], self.user.pk)
-        self.assertEqual(response.data['username'], self.user.username)
-        self.assertEqual(response.data['is_staff'], self.user.is_staff)
-        self.assertEqual(response.data['subscriptions'], [item.pk])
 
+class TestUserUserProfileAPIView(EndpointTester):
+    ''' Testing User profile views. '''
 
-class TestUserUserProfileAPIView(APITestCase):
     def setUp(self):
-        self.username = 'UserTest'
-        self.email = 'test@test.com'
-        self.password = 'password'
-        self.first_name = 'John'
-        self.user = User.objects.create_user(
-            self.username, self.email, self.password
-        )
-        self.user.first_name = self.first_name
+        super().setUp()
+        self.user.first_name = 'John'
+        self.user.second_name = 'Smith'
         self.user.save()
-        self.client = APIClient()
 
+
+    @decl_endpoint('/users/api/profile', method='get')
     def test_read_profile(self):
-        self.assertEqual(self.client.get('/users/api/profile').status_code, 403)
-        self.client.force_login(user=self.user)
-        response = self.client.get('/users/api/profile')
-        self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.data['username'], self.username)
-        self.assertEqual(response.data['email'], self.email)
-        self.assertEqual(response.data['first_name'], self.first_name)
-        self.assertEqual(response.data['last_name'], '')
+        response = self.executeOK()
+        self.assertEqual(response.data['username'], self.user.username)
+        self.assertEqual(response.data['email'], self.user.email)
+        self.assertEqual(response.data['first_name'], self.user.first_name)
+        self.assertEqual(response.data['last_name'], self.user.last_name)
 
-    def test_patch_profile(self):
-        self.client.force_login(user=self.user)
+        self.logout()
+        self.executeForbidden()
+
+
+    @decl_endpoint('/users/api/profile', method='patch')
+    def test_edit_profile(self):
         data = {
             'email': '123@mail.ru',
             'first_name': 'firstName',
             'last_name': 'lastName',
         }
-        response = self.client.patch(
-            '/users/api/profile',
-            data=data, format='json'
-        )
-        self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.data['email'], '123@mail.ru')
-        self.assertEqual(response.data['first_name'], 'firstName')
-        self.assertEqual(response.data['last_name'], 'lastName')
-
-    def test_edit_profile(self):
-        new_mail = 'newmail@gmail.com'
-        data = {'email': new_mail}
-        response = self.client.patch(
-            '/users/api/profile',
-            data=data, format='json'
-        )
-        self.assertEqual(response.status_code, 403)
-
-        self.client.force_login(user=self.user)
-        response = self.client.patch(
-            '/users/api/profile',
-            data=data, format='json'
-        )
-        self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.data['username'], self.username)
-        self.assertEqual(response.data['email'], new_mail)
-
-    def test_change_password(self):
-        newpassword = 'pw2'
-        data = {
-            'old_password': self.password,
-            'new_password': newpassword
-        }
-        response = self.client.patch(
-            '/users/api/change-password',
-            data=data, format='json'
-        )
-        self.assertEqual(response.status_code, 403)
-        self.assertFalse(self.client.login(username=self.user.username, password=newpassword))
-        self.assertTrue(self.client.login(username=self.user.username, password=self.password))
-
-        invalid = {
-            'old_password': 'invalid',
-            'new_password': newpassword
-        }
-        response = self.client.patch(
-            '/users/api/change-password',
-            data=invalid, format='json'
-        )
-        self.assertEqual(response.status_code, 400)
-
-        oldHash = self.user.password
-        self.client.force_login(user=self.user)
-        response = self.client.patch(
-            '/users/api/change-password',
-            data=data, format='json'
-        )
+        response = self.executeOK(data)
+        self.user.refresh_from_db()
+        self.assertEqual(response.data['email'], '123@mail.ru')
+        self.assertEqual(self.user.email, '123@mail.ru')
+        self.assertEqual(response.data['first_name'], 'firstName')
+        self.assertEqual(self.user.first_name, 'firstName')
+        self.assertEqual(response.data['last_name'], 'lastName')
+        self.assertEqual(self.user.last_name, 'lastName')
+
+        data = {
+            'email': data['email'],
+            'first_name': 'new',
+            'last_name': 'new2',
+        }
+        self.executeOK(data)
+
+        data = {'email': self.user2.email}
+        self.executeBadData(data)
+
+        self.logout()
+        self.executeForbidden()
+
+
+    @decl_endpoint('/users/api/change-password', method='patch')
+    def test_change_password(self):
+        data = {
+            'old_password': 'invalid',
+            'new_password': 'password2'
+        }
+        self.executeBadData(data)
+
+        data = {
+            'old_password': 'password',
+            'new_password': 'password2'
+        }
+        oldHash = self.user.password
+        response = self.executeNoContent(data)
         self.user.refresh_from_db()
-        self.assertEqual(response.status_code, 204)
         self.assertNotEqual(self.user.password, oldHash)
-        self.assertTrue(self.client.login(username=self.user.username, password=newpassword))
-        self.assertFalse(self.client.login(username=self.user.username, password=self.password))
+        self.assertTrue(self.client.login(username=self.user.username, password='password2'))
+        self.assertFalse(self.client.login(username=self.user.username, password='password'))
 
+        self.logout()
+        self.executeForbidden()
+
+
+    @decl_endpoint('/users/api/password-reset', method='post')
     def test_password_reset_request(self):
-        data = {
-            'email': 'invalid@gmail.com'
-        }
-        response = self.client.post(
-            '/users/api/password-reset',
-            data=data, format='json'
-        )
-        self.assertEqual(response.status_code, 400)
-
-        data = {
-            'email': self.email
-        }
-        response = self.client.post(
-            '/users/api/password-reset',
-            data=data, format='json'
-        )
-        self.assertEqual(response.status_code, 200)
+        self.executeBadData({'email': 'invalid@mail.ru'})
+        self.executeOK({'email': self.user.email})
+        # TODO: check if mail server actually sent email and if reset procedure works
 
 
-class TestSignupAPIView(APITestCase):
+class TestSignupAPIView(EndpointTester):
+    ''' Testing signup. '''
+
     def setUp(self):
-        self.client = APIClient()
+        super().setUp()
 
+
+    @decl_endpoint('/users/api/signup', method='post')
     def test_signup(self):
         data = {
-            'username': 'TestUser',
-            'email': 'email@mail.ru',
+            'username': 'NewUser',
+            'email': 'newMail@mail.ru',
+            'password': 'Test@@123',
+            'password2': 'Test@@123456',
+            'first_name': 'firstName',
+            'last_name': 'lastName'
+        }
+        self.executeBadData(data)
+
+        data = {
+            'username': 'NewUser',
+            'email': 'newMail@mail.ru',
             'password': 'Test@@123',
             'password2': 'Test@@123',
             'first_name': 'firstName',
-            'last_name': 'lastName',
+            'last_name': 'lastName'
         }
-        response = self.client.post(
-            '/users/api/signup',
-            data=data, format='json'
-        )
-        self.assertEqual(response.status_code, 201)
+        response = self.executeCreated(data)
         self.assertTrue('id' in response.data)
-        self.assertEqual(response.data['username'], 'TestUser')
-        self.assertEqual(response.data['email'], 'email@mail.ru')
-        self.assertEqual(response.data['first_name'], 'firstName')
-        self.assertEqual(response.data['last_name'], 'lastName')
+        self.assertEqual(response.data['username'], data['username'])
+        self.assertEqual(response.data['email'], data['email'])
+        self.assertEqual(response.data['first_name'], data['first_name'])
+        self.assertEqual(response.data['last_name'], data['last_name'])
+
+        data = {
+            'username': 'NewUser',
+            'email': 'newMail2@mail.ru',
+            'password': 'Test@@123',
+            'password2': 'Test@@123',
+            'first_name': 'firstName',
+            'last_name': 'lastName'
+        }
+        self.executeBadData(data)
+
+        data = {
+            'username': 'NewUser2',
+            'email': self.user.email,
+            'password': 'Test@@123',
+            'password2': 'Test@@123',
+            'first_name': 'firstName',
+            'last_name': 'lastName'
+        }
+        self.executeBadData(data)