add test + handle exception for unallowed subcontent content creation

backend/tracim_backend/tests/functional/test_workspaces.py

             status=400,
         )
 
+    def test_api__post_content_create_generic_content__err_400__unallowed_content_type(self) -> None:  # nopep8
+        """
+        Create generic content
+        """
+        dbsession = get_tm_session(self.session_factory, transaction.manager)
+        admin = dbsession.query(models.User) \
+            .filter(models.User.email == 'admin@admin.admin') \
+            .one()
+        workspace_api = WorkspaceApi(
+            current_user=admin,
+            session=dbsession,
+            config=self.app_config
+        )
+        content_api = ContentApi(
+            current_user=admin,
+            session=dbsession,
+            config=self.app_config
+        )
+        test_workspace = workspace_api.create_workspace(
+            label='test',
+            save_now=True,
+        )
+        folder = content_api.create(
+            label='test-folder',
+            content_type_slug=CONTENT_TYPES.Folder.slug,
+            workspace=test_workspace,
+            do_save=False,
+            do_notify=False
+        )
+        content_api.set_allowed_content(folder, [CONTENT_TYPES.Folder.slug])
+        content_api.save(folder)
+        transaction.commit()
+        self.testapp.authorization = (
+            'Basic',
+            (
+                'admin@admin.admin',
+                'admin@admin.admin'
+            )
+        )
+        # unallowed_content_type
+        params = {
+            'label': 'GenericCreatedContent',
+            'content_type': 'markdownpage',
+            'parent_id': folder.content_id
+        }
+        res = self.testapp.post_json(
+            '/api/v2/workspaces/{workspace_id}/contents'.format(workspace_id=test_workspace.workspace_id),
+            params=params,
+            status=400,
+        )
+
+        # allowed_content_type
+        params = {
+            'label': 'GenericCreatedContent',
+            'content_type': 'folder',
+            'parent_id': folder.content_id
+        }
+        res = self.testapp.post_json(
+            '/api/v2/workspaces/{workspace_id}/contents'.format(workspace_id=test_workspace.workspace_id),
+            params=params,
+            status=200,
+        )
+
     def test_api_put_move_content__ok_200__nominal_case(self):
         """
         Move content

backend/tracim_backend/views/core_api/workspace_controller.py

 from tracim_backend.models.data import ActionDescription
 from tracim_backend.models.context_models import UserRoleWorkspaceInContext
 from tracim_backend.models.context_models import ContentInContext
-from tracim_backend.exceptions import EmptyLabelNotAllowed
+from tracim_backend.exceptions import EmptyLabelNotAllowed, UnallowedSubContent
 from tracim_backend.exceptions import EmailValidationFailed
 from tracim_backend.exceptions import UserCreationFailed
 from tracim_backend.exceptions import UserDoesNotExist
     @hapic.with_api_doc(tags=[SWAGGER_TAG_WORKSPACE_ENDPOINTS])
     @require_workspace_role(UserRoleInWorkspace.CONTRIBUTOR)
     @hapic.handle_exception(EmptyLabelNotAllowed, HTTPStatus.BAD_REQUEST)
+    @hapic.handle_exception(UnallowedSubContent, HTTPStatus.BAD_REQUEST)
     @hapic.input_path(WorkspaceIdPathSchema())
     @hapic.input_body(ContentCreationSchema())
     @hapic.output_body(ContentDigestSchema())