Make get_stats_sum return dict instead of AggregatedStats instance

Django 3.2 throws an error when instantiating an abstract model.
This commit also adds tests for the views that were previously not covered.

pontoon/base/models.py

@@ -428,14 +428,14 @@ def get_stats_sum(cls, qs):
         """
         Get sum of stats for all items in the queryset.
         """
-        return cls(
-            total_strings=sum(x.total_strings for x in qs),
-            approved_strings=sum(x.approved_strings for x in qs),
-            fuzzy_strings=sum(x.fuzzy_strings for x in qs),
-            strings_with_errors=sum(x.strings_with_errors for x in qs),
-            strings_with_warnings=sum(x.strings_with_warnings for x in qs),
-            unreviewed_strings=sum(x.unreviewed_strings for x in qs),
-        )
+        return {
+            "total_strings": sum(x.total_strings for x in qs),
+            "approved_strings": sum(x.approved_strings for x in qs),
+            "fuzzy_strings": sum(x.fuzzy_strings for x in qs),
+            "strings_with_errors": sum(x.strings_with_errors for x in qs),
+            "strings_with_warnings": sum(x.strings_with_warnings for x in qs),
+            "unreviewed_strings": sum(x.unreviewed_strings for x in qs),
+        }
 
     @classmethod
     def get_top_instances(cls, qs):

pontoon/projects/tests/test_views.py

@@ -4,12 +4,17 @@
 from django.http import HttpResponse
 from django.shortcuts import render
 
-from pontoon.base.models import Project
-from pontoon.base.tests import (
-    ProjectFactory,
-    ResourceFactory,
-    TranslationFactory,
-)
+from pontoon.base.tests import TranslationFactory
+
+
+@pytest.mark.django_db
+def test_projects_list(client, project_a, resource_a):
+    """
+    Checks if list of projects is properly rendered.
+    """
+    response = client.get("/projects/")
+    assert response.status_code == 200
+    assert response.resolver_match.view_name == "pontoon.projects"
 
 
 @pytest.mark.django_db
@@ -24,53 +29,46 @@ def test_project_doesnt_exist(client):
 
 
 @pytest.mark.django_db
-def test_project_view(client):
+def test_project_view(client, project_a, resource_a):
     """
     Checks if project page is returned properly.
     """
-    project = ProjectFactory.create(visibility=Project.Visibility.PUBLIC)
-    ResourceFactory.create(project=project)
-
     with patch("pontoon.projects.views.render", wraps=render) as mock_render:
-        client.get(f"/projects/{project.slug}/")
-        assert mock_render.call_args[0][2]["project"] == project
+        client.get(f"/projects/{project_a.slug}/")
+        assert mock_render.call_args[0][2]["project"] == project_a
 
 
 @pytest.mark.django_db
-def test_project_top_contributors(client):
+def test_project_top_contributors(client, project_a, project_b):
     """
     Tests if view returns top contributors specific for given project.
     """
-    first_project = ProjectFactory.create(visibility=Project.Visibility.PUBLIC)
-    ResourceFactory.create(project=first_project)
-    first_project_contributor = TranslationFactory.create(
-        entity__resource__project=first_project
+    project_a_contributor = TranslationFactory.create(
+        entity__resource__project=project_a
     ).user
 
-    second_project = ProjectFactory.create(visibility=Project.Visibility.PUBLIC)
-    ResourceFactory.create(project=second_project)
-    second_project_contributor = TranslationFactory.create(
-        entity__resource__project=second_project
+    project_b_contributor = TranslationFactory.create(
+        entity__resource__project=project_b
     ).user
 
     with patch(
         "pontoon.projects.views.ProjectContributorsView.render_to_response",
         return_value=HttpResponse(""),
     ) as mock_render:
         client.get(
-            f"/projects/{first_project.slug}/ajax/contributors/",
+            f"/projects/{project_a.slug}/ajax/contributors/",
             HTTP_X_REQUESTED_WITH="XMLHttpRequest",
         )
-        assert mock_render.call_args[0][0]["project"] == first_project
+        assert mock_render.call_args[0][0]["project"] == project_a
         assert list(mock_render.call_args[0][0]["contributors"]) == [
-            first_project_contributor
+            project_a_contributor
         ]
 
         client.get(
-            f"/projects/{second_project.slug}/ajax/contributors/",
+            f"/projects/{project_b.slug}/ajax/contributors/",
             HTTP_X_REQUESTED_WITH="XMLHttpRequest",
         )
-        assert mock_render.call_args[0][0]["project"] == second_project
+        assert mock_render.call_args[0][0]["project"] == project_b
         assert list(mock_render.call_args[0][0]["contributors"]) == [
-            second_project_contributor
+            project_b_contributor
         ]

pontoon/teams/tests/test_views.py

@@ -22,6 +22,16 @@ def managers():
     return _get_sorted_users()
 
 
+@pytest.mark.django_db
+def test_teams_list(client, locale_a):
+    """
+    Tests if the teams list is rendered properly.
+    """
+    response = client.get("/teams/")
+    assert response.status_code == 200
+    assert response.resolver_match.view_name == "pontoon.teams"
+
+
 @pytest.mark.django_db
 def test_missing_locale(client):
     """