Added unit tests for notices functions

features/unattached_status.feature

@@ -599,3 +599,38 @@ Feature: Unattached status
         Examples: ubuntu release
            | release | machine_type  |
            | jammy   | lxd-container |
+
+    Scenario Outline: Check notice file read permission
+        Given a `<release>` `<machine_type>` machine with ubuntu-advantage-tools installed
+        When I run `rm -rf /run/ubuntu-advantage` with sudo
+        When I run `mkdir -p /run/ubuntu-advantage/notices` with sudo
+        When I run `touch /run/ubuntu-advantage/notices/crasher` with sudo
+        When I run `chmod 0 /run/ubuntu-advantage/notices/crasher` with sudo
+        When I run `rm -rf /var/ubuntu-advantage` with sudo
+        When I run `mkdir -p /var/ubuntu-advantage/notices` with sudo
+        When I run `touch /var/ubuntu-advantage/notices/crasher` with sudo
+        When I run `chmod 0 /var/ubuntu-advantage/notices/crasher` with sudo
+        When I run `pro status` as non-root
+        Then stdout matches regexp:
+        """
+        SERVICE         +AVAILABLE +DESCRIPTION
+        (anbox-cloud   +(yes|no)  +.*)?
+        ?cc-eal          +yes       +Common Criteria EAL2 Provisioning Packages
+        cis             +yes       +Security compliance and audit tools
+        esm-apps        +yes       +Expanded Security Maintenance for Applications
+        esm-infra       +yes       +Expanded Security Maintenance for Infrastructure
+        fips            +yes       +NIST-certified FIPS crypto packages
+        fips-updates    +yes       +FIPS compliant crypto packages with stable security updates
+        livepatch       +yes      +(Canonical Livepatch service|Current kernel is not supported)
+        ros             +yes       +Security Updates for the Robot Operating System
+        ros-updates     +yes       +All Updates for the Robot Operating System
+
+        For a list of all Ubuntu Pro services, run 'pro status --all'
+
+        This machine is not attached to an Ubuntu Pro subscription.
+        See https://ubuntu.com/pro
+        """
+        Examples: ubuntu release
+            | release | machine_type  |
+            | xenial  | lxd-container |
+            | bionic  | lxd-container |

uaclient/files/notices.py

@@ -181,17 +181,6 @@ def _is_readable(self, directory: str, file_name: str) -> bool:
         """
         return os.access(os.path.join(directory, file_name), os.R_OK)
 
-    def _load_notice_file_contents(
-        self, directory: str, file_name: str
-    ) -> str:
-        """Loads the contents of the notice file.
-
-        :param directory: The directory where the notice file is located.
-        :param file_name: The name of the notice file.
-        :returns: The contents of the notice file.
-        """
-        return system.load_file(os.path.join(directory, file_name))
-
     def _get_default_message(self, file_name: str) -> str:
         """Gets the default message for a notice file.
 
@@ -231,9 +220,15 @@ def list(self) -> List[str]:
             for notice_file_name in notice_file_names:
                 if not self._is_readable(notice_directory, notice_file_name):
                     continue
-                notice_file_contents = self._load_notice_file_contents(
-                    notice_directory, notice_file_name
-                )
+                try:
+                    notice_file_contents = system.load_file(
+                        os.path.join(notice_directory, notice_file_name)
+                    )
+                except PermissionError:
+                    LOG.warning(
+                        f"Permission error while reading {notice_file_name}"
+                    )
+                    continue
                 if notice_file_contents:
                     notices.append(notice_file_contents)
                 else:

uaclient/files/tests/test_notices.py

@@ -124,3 +124,38 @@ def test_notice_module(
         assert [mock.call(FakeNotice.a)] == notice_cls_remove.call_args_list
         notices.list()
         assert 1 == notice_cls_read.call_count
+
+    @mock.patch("uaclient.files.notices.NoticesManager._get_notice_file_names")
+    def test_get_notice_file_names(self, m_get_notice_file_names):
+        notice = NoticesManager()
+        m_get_notice_file_names.return_value = []
+        assert [] == notice._get_notice_file_names("directory")
+        m_get_notice_file_names.return_value = ["file1", "file2", "file3"]
+        assert ["file1", "file2", "file3"] == notice._get_notice_file_names(
+            "directory"
+        )
+
+    @mock.patch("uaclient.files.notices.os.access")
+    def test_is_readable(self, m_access):
+        notice = NoticesManager()
+        m_access.return_value = False
+        assert not notice._is_readable("directory", "file")
+        assert [] == notice.list()
+        m_access.assert_called_once_with("directory/file", os.R_OK)
+
+    @mock.patch("uaclient.files.notices.NoticesManager._get_notice_file_names")
+    @mock.patch("uaclient.files.notices.NoticesManager._is_readable")
+    @mock.patch("uaclient.system.load_file")
+    def test_list(self, m_load_file, m_is_readable, m_get_notice_file_names):
+        notice = NoticesManager()
+
+        m_get_notice_file_names.side_effect = (
+            lambda directory: []
+            if directory == defaults.NOTICES_TEMPORARY_DIRECTORY
+            else ["fakeNotice1", "fakeNotice2"]
+        )
+        m_is_readable.side_effect = [True, False]
+        m_load_file.return_value = "test"
+
+        assert ["test"] == notice.list()
+        assert 2 == notice._is_readable.call_count