netbsd add unit-test for case pkgin is present

tests/unittests/test_distros/test_netbsd.py

@@ -1,25 +1,21 @@
-import os.path
-
 import cloudinit.distros.netbsd
 
+import unittest.mock as mock
 
-real_path_exists = os.path.exists
-def _pkgin_exists_factory(expectation):
-    def _mock_exists(path):
-        if path.endswith("/pkgin"):
-            return expectation
-        return real_path_exists(path)
-    return _mock_exists
 
-def test_init_and_pkgin(monkeypatch):
+@mock.patch("cloudinit.distros.netbsd.os")
+def test_init_with_pkgin(m_os):
+    m_os.path.exists.return_value = True
     cfg = {}
 
-    with monkeypatch.context() as m:
-        m.setattr(os.path, "exists", _pkgin_exists_factory(True))
-        distro = cloudinit.distros.netbsd.NetBSD("netbsd", cfg, None)
-        assert distro.pkg_cmd_upgrade_prefix == ['pkgin', '-y', 'full-upgrade']
+    distro = cloudinit.distros.netbsd.NetBSD("netbsd", cfg, None)
+    assert distro.pkg_cmd_upgrade_prefix == ['pkgin', '-y', 'full-upgrade']
+
+
+@mock.patch("cloudinit.distros.netbsd.os")
+def test_init_without_pkgin(m_os):
+    m_os.path.exists.return_value = False
+    cfg = {}
 
-        m.setattr(os.path, "exists", _pkgin_exists_factory(False))
-        distro = cloudinit.distros.netbsd.NetBSD("netbsd", cfg, None)
-        print(distro.pkg_cmd_upgrade_prefix)
-        assert distro.pkg_cmd_upgrade_prefix == None
+    distro = cloudinit.distros.netbsd.NetBSD("netbsd", cfg, None)
+    assert distro.pkg_cmd_upgrade_prefix is None