permissions: check user permissions for host delete

SAT-21619 (component evaluation).

Check for correct user permissions when deleting a host.

Because a host deletion action has defined multiple permissions,
following modifications have been done:

- function `_permission_name` renamed to `_permission_names` and returns list instead of string
- new method `TestUserRole.give_user_permissions` that works well with `_permission_names`

tests/foreman/api/test_permission.py

@@ -161,18 +161,20 @@ def test_positive_search(self, target_sat):
 
 # FIXME: This method is a hack. This information should somehow be tied
 # directly to the `Entity` classes.
-def _permission_name(entity, which_perm):
-    """Find a permission name.
+def _permission_names(entity, which_perm: str) -> list:
+    """Find a permission names.
 
-    Attempt to locate a permission in :data:`robottelo.constants.PERMISSIONS`.
-    For example, return 'view_architectures' if ``entity`` is ``Architecture``
-    and ``which_perm`` is 'read'.
+    Attempt to locate permissions in :data:`robottelo.constants.PERMISSIONS`.
+
+    Examples:
+        _permission_names('Architecture', 'read') -> ['view_architectures']
+        _permission_names('Host', 'delete') -> ['destroy_discovered_hosts', 'destroy_hosts']
 
     :param entity: A ``nailgun.entity_mixins.Entity`` subclass.
     :param str which_perm: Either the word "create", "read", "update" or
         "delete".
-    :raise: ``LookupError`` if a relevant permission cannot be found, or if
-        multiple results are found.
+    :raise: ``LookupError`` if a relevant permission cannot be found
+    :returns: list of found permission names
     """
     pattern = {'create': '^create_', 'delete': '^destroy_', 'read': '^view_', 'update': '^edit_'}[
         which_perm
@@ -181,11 +183,11 @@ def _permission_name(entity, which_perm):
     permissions = PERMISSIONS.get(entity.__name__) or PERMISSIONS.get(f'Katello::{entity.__name__}')
     for permission in permissions:
         match = re.match(pattern, permission)
-        if match is not None:
+        if match:
             perm_names.append(permission)
-    if len(perm_names) != 1:
-        raise LookupError(f'Could not find the requested permission. Found: {perm_names}')
-    return perm_names[0]
+    if not perm_names:
+        raise LookupError(f'Could not find any "{which_perm}" permission for entity "{entity}"')
+    return perm_names
 
 
 # This class might better belong in module test_multiple_paths.
@@ -226,6 +228,15 @@ def give_user_permission(self, perm_name, target_sat):
         self.user.role += [role]
         self.user = self.user.update(['role'])
 
+    def give_user_permissions(self, perm_names, target_sat):
+        """Give ``self.user`` multiple permissions.
+        Otherwise, works the same as method ``self.give_user_permission``.
+
+        :param list perm_names: permission names
+        """
+        for perm_name in perm_names:
+            self.give_user_permission(perm_name, target_sat)
+
     def set_taxonomies(self, entity, organization=None, location=None):
         """Set organization and location for entity if it supports them.
 
@@ -273,7 +284,7 @@ def test_positive_check_create(self, entity_cls, class_org, class_location, targ
         """
         with pytest.raises(HTTPError):
             entity_cls(self.cfg).create()
-        self.give_user_permission(_permission_name(entity_cls, 'create'), target_sat)
+        self.give_user_permissions(_permission_names(entity_cls, 'create'), target_sat)
         new_entity = self.set_taxonomies(entity_cls(self.cfg), class_org, class_location)
         # Entities with both org and loc require
         # additional permissions to set them.
@@ -307,14 +318,16 @@ def test_positive_check_read(self, entity_cls, class_org, class_location, target
         new_entity = new_entity.create()
         with pytest.raises(HTTPError):
             entity_cls(self.cfg, id=new_entity.id).read()
-        self.give_user_permission(_permission_name(entity_cls, 'read'), target_sat)
+        self.give_user_permissions(_permission_names(entity_cls, 'read'), target_sat)
         entity_cls(self.cfg, id=new_entity.id).read()
 
     @pytest.mark.upgrade
     @pytest.mark.tier1
     @pytest.mark.parametrize(
         'entity_cls',
-        **parametrized([entities.Architecture, entities.Domain, entities.ActivationKey]),
+        **parametrized(
+            [entities.Architecture, entities.Domain, entities.ActivationKey, entities.Host]
+        ),
     )
     def test_positive_check_delete(self, entity_cls, class_org, class_location, target_sat):
         """Check whether the "destroy_*" role has an effect.
@@ -334,7 +347,7 @@ def test_positive_check_delete(self, entity_cls, class_org, class_location, targ
         new_entity = new_entity.create()
         with pytest.raises(HTTPError):
             entity_cls(self.cfg, id=new_entity.id).delete()
-        self.give_user_permission(_permission_name(entity_cls, 'delete'), target_sat)
+        self.give_user_permissions(_permission_names(entity_cls, 'delete'), target_sat)
         entity_cls(self.cfg, id=new_entity.id).delete()
         with pytest.raises(HTTPError):
             new_entity.read()  # As admin user
@@ -371,7 +384,7 @@ def test_positive_check_update(self, entity_cls, class_org, class_location, targ
             update_entity = entity_cls(self.cfg, id=new_entity.id, name=name)
         with pytest.raises(HTTPError):
             update_entity.update(['name'])
-        self.give_user_permission(_permission_name(entity_cls, 'update'), target_sat)
+        self.give_user_permissions(_permission_names(entity_cls, 'update'), target_sat)
         # update() calls read() under the hood, which triggers
         # permission error
         if entity_cls is entities.ActivationKey: