feat: switch off the fix templates QTS cannot take (0.4.0)

napalm-linux 0.8 implements napalm-device-types' fix templates. QTS has
no apt, dnf or opkg and sets its SNMP agent in its own UI, so
configure_snmp_agent, configure_package_proxy and ensure_package are
None here: a capability check answers no instead of offering a fix
that fails, as the inherited fix_snmp and fix_apt_proxy did.

get_device_warnings returns nothing: the inherited one asked for
updates, which is None here, and logged a TypeError on every poll.

The role test follows napalm-linux's get_os_users.

Closes #6. Part of #7.

tests/test_qnap_qts.py

@@ -10,8 +10,8 @@ from __future__ import annotations
 from unittest.mock import MagicMock, patch
 
 import pytest
-
 from napalm_device_types import primary_role_of, role_keys_of
+
 from napalm_qnap_qts import QnapQtsDriver
 
 #: Parsers need real command output to be written against. These tests are the
@@ -97,7 +97,7 @@ class TestRolesDoNotShadowLinux:
     collision. There is nothing left to collide with.
     """
 
-    @pytest.mark.parametrize("method", ["get_services", "get_users"])
+    @pytest.mark.parametrize("method", ["get_services", "get_os_users"])
     def test_os_surface_resolves_to_linux(self, method):
         """QTS really is Linux for these, so inheriting them is correct."""
         from napalm_linux.linux import LinuxDriver
@@ -224,3 +224,22 @@ def test_updates_are_not_read_or_applied_here():
     methods are callable."""
     for method in ("get_available_updates", "refresh_available_updates", "apply_updates"):
         assert not callable(getattr(QnapQtsDriver, method, None)), method
+
+
+class TestFixesQtsCannotTake:
+    """QTS has no apt, dnf or opkg, and its SNMP agent is configured in its own UI:
+    the fix templates inherited from LinuxDriver are switched off (#7), so a
+    capability check -- is it callable? -- answers no."""
+
+    @pytest.mark.parametrize(
+        "name", ["configure_snmp_agent", "configure_package_proxy", "ensure_package"]
+    )
+    def test_switched_off(self, name):
+        assert getattr(QnapQtsDriver, name) is None
+
+
+def test_device_warnings_do_not_ask_for_updates_qts_cannot_list():
+    """The inherited get_device_warnings called get_available_updates, which is
+    None here, and logged a TypeError on every poll (#6)."""
+    driver = QnapQtsDriver("nas", "admin", "pw")
+    assert driver.get_device_warnings() == []