Moved responsibility of system_information collection

Now the collection is done automatically upon the first get call
if no set was done previously. This should be effectively the same as
before, the first checkpoint dumps the information, reading it, while
a non-fresh session will load a checkpoint setting before reading it

Minor: Update tests to mock/check the new path

checkbox-ng/plainbox/impl/session/assistant.py

@@ -66,7 +66,6 @@
 from plainbox.impl.transport import TransportError
 from plainbox.impl.unit.exporter import ExporterError
 from plainbox.impl.unit.unit import Unit
-from plainbox.impl.session import system_information
 from plainbox.vendor import morris
 
 _logger = logging.getLogger("plainbox.session.assistant")
@@ -501,9 +500,6 @@ def start_new_session(
         self._metadata.app_id = self._app_id
         self._metadata.title = title
         self._metadata.flags = {SessionMetaData.FLAG_BOOTSTRAPPING}
-
-        self._manager.state.update_system_information(system_information.collect())
-
         self._manager.checkpoint()
         self._command_io_delegate = JobRunnerUIDelegate(_SilentUI())
         self._init_runner(runner_cls, runner_kwargs)

checkbox-ng/plainbox/impl/session/resume.py

@@ -1187,7 +1187,7 @@ def _restore_SessionState_system_information(self, session_state, session_repr):
                 "system_information"
             ].items()
         }
-        session_state.update_system_information(system_information)
+        session_state.system_information = system_information
 
     def _build_SessionState(self, session_repr, early_cb=None):
         session_state = super()._build_SessionState(session_repr, early_cb)

checkbox-ng/plainbox/impl/session/state.py

@@ -35,6 +35,9 @@
 from plainbox.impl.secure.qualifiers import select_jobs
 from plainbox.impl.session.jobs import JobState
 from plainbox.impl.session.jobs import UndesiredJobReadinessInhibitor
+from plainbox.impl.session.system_information import(
+    collect as collect_system_information
+)
 from plainbox.impl.unit.job import JobDefinition
 from plainbox.impl.unit.unit_with_id import UnitWithId
 from plainbox.impl.unit.testplan import TestPlanUnitSupport
@@ -746,7 +749,9 @@ def __init__(self, unit_list):
         self._resource_map = {}
         self._fake_resources = False
         self._metadata = SessionMetaData()
-        self._system_information = {}
+        # If unset, this is loaded via system_information
+        self._system_information = None
+
         super(SessionState, self).__init__()
 
     def trim_job_list(self, qualifier):
@@ -816,14 +821,17 @@ def trim_job_list(self, qualifier):
                 self.on_job_removed(job)
                 self.on_unit_removed(job)
 
-    def update_system_information(self, system_information):
-        """
-        Update the system information with every tool and its output.
+    @property
+    def system_information(self):
+        if not self._system_information:
+            # This is a new session, we need to query this infos
+            self._system_information = collect_system_information()
+        return self._system_information
 
-        This method simply stores the dict of system_information jobs inside
-        the session state.
-        """
-        self._system_information = system_information
+    @system_information.setter
+    def system_information(self, value):
+        #TODO: check if system_information was already set
+        self._system_information = value
 
     def update_mandatory_job_list(self, mandatory_job_list):
         """
@@ -1181,13 +1189,6 @@ def set_resource_list(self, resource_id, resource_list):
         """
         self._resource_map[resource_id] = resource_list
 
-    @property
-    def system_information(self):
-        """
-        Dict of all system information.
-        """
-        return self._system_information
-
     @property
     def job_list(self):
         """

checkbox-ng/plainbox/impl/session/test_assistant.py

@@ -68,7 +68,7 @@ def test_expected_call_sequence(self, mock_get_providers):
                       UsageExpectation.of(self.sa).allowed_calls)
         # patch system_information to avoid the actual collection of
         # system_information in tests
-        with mock.patch("plainbox.impl.session.assistant.system_information"):
+        with mock.patch("plainbox.impl.session.state.SessionState.system_information"):
             # Call SessionAssistant.start_new_session()
             self.sa.start_new_session("just for testing")
         # SessionAssistant.start_new_session() must no longer allowed

checkbox-ng/plainbox/impl/session/test_resume.py

@@ -510,19 +510,20 @@ def test_calls_restore_SessionState_system_information(self):
         self_mock = mock.MagicMock()
         session_state_mock = mock.MagicMock()
 
-        session_repr = {
-            "system_information": {
-            }
-        }
+        session_repr = {"system_information": {}}
 
         SessionResumeHelper8._restore_SessionState_system_information(
             self_mock, session_state_mock, session_repr
         )
 
-        session_state_mock.update_system_information.assert_called_once_with(
-            {}
-        )
-    def test_calls_build_SessionState(self):
+        with mock.patch(
+            "plainbox.impl.session.system_information.collect"
+        ) as collect_mock:
+            _ = session_state_mock.system_information
+            self.assertFalse(collect_mock.called)
+
+    @mock.patch("plainbox.impl.session.system_information.collect")
+    def test_calls_build_SessionState(self, collect_mock):
         # mock super to avoid super._build_SessionState call in this test
         with mock.patch(
             "plainbox.impl.session.resume.SessionResumeHelper7._build_SessionState"
@@ -531,7 +532,8 @@ def test_calls_build_SessionState(self):
             session_state = session_resume_helper._build_SessionState({
                 "system_information" : {}
             })
-        self.assertTrue(session_state.update_system_information.called)
+        self.assertNotEqual(session_state.system_information, None)
+        self.assertFalse(collect_mock.called)
 
 class SessionStateResumeTests(TestCaseWithParameters):
     """