ISD-1514 Add unit tests, set coverage target to 95 (#17)

Co-authored-by: arturo-seijas <[email protected]>

pyproject.toml

@@ -11,7 +11,7 @@ skips = ["*/*test.py", "*/test_*.py", "*tests/*.py"]
 branch = true
 
 [tool.coverage.report]
-# fail_under = 99
+fail_under = 95
 show_missing = true
 
 [tool.pytest.ini_options]

tests/unit/conftest.py

@@ -3,10 +3,28 @@
 """Fixtures for jenkins-agent charm tests."""
 
 
+import secrets
+
 import pytest
 from ops.testing import Harness
 
 from charm import JenkinsAgentCharm
+from charm_state import AGENT_RELATION
+
+
+@pytest.fixture(scope="module", name="agent_relation_data")
+def agent_relation_data_fixture() -> dict:
+    """Mock relation data for agent relation."""
+    return {"url": "http://example.com", "jenkins-agent-0_secret": secrets.token_hex(4)}
+
+
+@pytest.fixture(scope="module", name="service_configuration_template")
+def service_configuration_template_fixture(agent_relation_data: dict) -> str:
+    """Mock service environment variables configuration for jenkins-agent."""
+    return f'''[Service]
+Environment="JENKINS_TOKEN={agent_relation_data.get('jenkins-agent-0_secret')}"
+Environment="JENKINS_URL={agent_relation_data.get('url')}"
+Environment="JENKINS_AGENT=jenkins-agent-0"'''
 
 
 @pytest.fixture(scope="function", name="harness")
@@ -17,3 +35,17 @@ def harness_fixture():
     yield harness
 
     harness.cleanup()
+
+
+@pytest.fixture(scope="function", name="harness_with_agent_relation")
+def harness_with_agent_relation_fixture(harness: Harness, agent_relation_data: dict) -> Harness:
+    """Harness with agent relation to jenkins-k8s.
+
+    Args:
+        harness the default testing harness.
+
+    Returns:
+        The harness with agent relation established.
+    """
+    harness.add_relation(AGENT_RELATION, "jenkins-k8s", unit_data=agent_relation_data)
+    return harness

tests/unit/test_agent.py

@@ -0,0 +1,154 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+#
+# Learn more about testing at: https://juju.is/docs/sdk/testing
+
+"""Test for agent relations."""
+
+from unittest.mock import MagicMock, PropertyMock
+
+import ops.testing
+import pytest
+from charms.operator_libs_linux.v1 import systemd
+
+import service
+from charm import JenkinsAgentCharm
+from charm_state import AGENT_RELATION
+
+
+def test_agent_relation_joined(harness: ops.testing.Harness, agent_relation_data: dict):
+    """
+    arrange: initialized jenkins-agent charm.
+    act: add relation to the jenkins-k8s charm.
+    assert: The agent set the correct information in the unit's relation databag.
+    """
+    harness.begin()
+    relation_id = harness.add_relation(
+        AGENT_RELATION, "jenkins-k8s", unit_data=agent_relation_data
+    )
+    charm: JenkinsAgentCharm = harness.charm
+    assert (
+        harness.get_relation_data(relation_id, app_or_unit="jenkins-agent/0")
+        == charm.state.agent_meta.as_dict()
+    )
+
+
+def test_agent_relation_changed_service_restart(
+    harness_with_agent_relation: ops.testing.Harness,
+    monkeypatch: pytest.MonkeyPatch,
+    agent_relation_data: dict,
+):
+    """
+    arrange: initialized jenkins-agent charm related to jenkins-k8s charm with relation data.
+    act: Trigger _on_agent_relation_changed hook.
+    assert: The charm should be in active state.
+    """
+    harness = harness_with_agent_relation
+    harness.begin()
+    charm: JenkinsAgentCharm = harness.charm
+    monkeypatch.setattr(charm.jenkins_agent_service, "restart", MagicMock())
+
+    charm.on.agent_relation_changed.emit(harness.model.get_relation(AGENT_RELATION))
+
+    assert charm.state.agent_relation_credentials
+    assert (
+        charm.state.agent_relation_credentials.secret
+        == agent_relation_data["jenkins-agent-0_secret"]
+    )
+    assert charm.state.agent_relation_credentials.address == agent_relation_data["url"]
+    assert charm.unit.status.name == ops.ActiveStatus.name
+
+
+def test_agent_relation_changed_service_restart_error(
+    harness_with_agent_relation: ops.testing.Harness,
+    monkeypatch: pytest.MonkeyPatch,
+    agent_relation_data: dict,
+):
+    """
+    arrange: initialized jenkins-agent charm related to jenkins-k8s charm with relation data.
+    act: Trigger _on_agent_relation_changed hook with restart throwing an exception.
+    assert: The charm should be in error state with the correct error message.
+    """
+    harness = harness_with_agent_relation
+    harness.begin()
+
+    charm: JenkinsAgentCharm = harness.charm
+    assert charm.state.agent_relation_credentials
+    assert (
+        charm.state.agent_relation_credentials.secret
+        == agent_relation_data["jenkins-agent-0_secret"]
+    )
+    assert charm.state.agent_relation_credentials.address == agent_relation_data["url"]
+
+    monkeypatch.setattr(
+        charm.jenkins_agent_service, "restart", MagicMock(side_effect=service.ServiceRestartError)
+    )
+    with pytest.raises(RuntimeError, match="Error restarting the agent service."):
+        harness.charm.on.agent_relation_changed.emit(harness.model.get_relation(AGENT_RELATION))
+
+
+def test_agent_relation_changed_service_already_active(
+    harness_with_agent_relation: ops.testing.Harness,
+    monkeypatch: pytest.MonkeyPatch,
+):
+    """
+    arrange: initialized jenkins-agent charm related to jenkins-k8s charm with relation data.
+    act: Trigger _on_agent_relation_changed hook when the service is already up.
+    assert: The charm skips restarting the agent service.
+    """
+    service_restart_mock = MagicMock()
+    service_is_active_mock = PropertyMock(return_value=True)
+    monkeypatch.setattr(service.JenkinsAgentService, "restart", service_restart_mock)
+    monkeypatch.setattr(service.JenkinsAgentService, "is_active", service_is_active_mock)
+    harness = harness_with_agent_relation
+    harness.begin()
+
+    harness.charm.on.agent_relation_changed.emit(harness.model.get_relation(AGENT_RELATION))
+
+    assert service_is_active_mock.call_count == 1
+    assert service_restart_mock.call_count == 0
+
+
+def test_agent_relation_departed_service_stop_error(
+    harness_with_agent_relation: ops.testing.Harness, monkeypatch: pytest.MonkeyPatch
+):
+    """
+    arrange: initialized jenkins-agent charm related to jenkins-k8s charm with relation data.
+    act: remove the relation, raising an error when stopping the agent service.
+    assert: The charm falls into BlockedStatus with the correct message.
+    """
+    monkeypatch.setattr(systemd, "service_stop", MagicMock(side_effect=systemd.SystemdError))
+
+    harness = harness_with_agent_relation
+    harness.begin()
+
+    relation = harness.model.get_relation(AGENT_RELATION)
+    assert relation
+    harness.remove_relation(relation_id=relation.id)
+
+    charm: JenkinsAgentCharm = harness.charm
+    assert charm.unit.status.name == ops.BlockedStatus.name
+    assert charm.unit.status.message == "Error stopping the agent service"
+
+
+def test_agent_relation_departed(
+    harness_with_agent_relation: ops.testing.Harness,
+    monkeypatch: pytest.MonkeyPatch,
+):
+    """
+    arrange: initialized jenkins-agent charm related to jenkins-k8s charm with relation data.
+    act: remove the relation.
+    assert: The charm falls into BlockedStatus with the correct message.
+    """
+    monkeypatch.setattr(systemd, "service_stop", MagicMock())
+
+    harness = harness_with_agent_relation
+    harness.begin()
+
+    relation = harness.model.get_relation(AGENT_RELATION)
+    assert relation
+    harness.remove_relation(relation_id=relation.id)
+
+    charm: JenkinsAgentCharm = harness.charm
+    assert charm.unit.status.name == ops.BlockedStatus.name
+    assert charm.unit.status.message == "Waiting for config/relation."

tests/unit/test_charm.py

@@ -3,7 +3,6 @@
 #
 # Learn more about testing at: https://juju.is/docs/sdk/testing
 
-# pylint: disable=protected-access
 """Test for charm hooks."""
 
 from unittest.mock import MagicMock
@@ -17,18 +16,6 @@
 from charm import JenkinsAgentCharm
 
 
-def raise_exception(exception: Exception):
-    """Raise exception function for monkeypatching.
-
-    Args:
-        exception: The exception to raise.
-
-    Raises:
-        exception: .
-    """
-    raise exception
-
-
 def test___init___invalid_state(harness: ops.testing.Harness, monkeypatch: pytest.MonkeyPatch):
     """
     arrange: patched State.from_charm that raises an InvalidState Error.
@@ -43,9 +30,9 @@ def test___init___invalid_state(harness: ops.testing.Harness, monkeypatch: pytes
 
     harness.begin()
 
-    jenkins_charm: JenkinsAgentCharm = harness.charm
-    assert jenkins_charm.unit.status.name == ops.BlockedStatus.name
-    assert jenkins_charm.unit.status.message == "Invalid executor message"
+    charm: JenkinsAgentCharm = harness.charm
+    assert charm.unit.status.name == ops.BlockedStatus.name
+    assert charm.unit.status.message == "Invalid executor message"
 
 
 def test__on_upgrade_charm(harness: ops.testing.Harness, monkeypatch: pytest.MonkeyPatch):
@@ -58,12 +45,11 @@ def test__on_upgrade_charm(harness: ops.testing.Harness, monkeypatch: pytest.Mon
     monkeypatch.setattr(service.JenkinsAgentService, "restart", MagicMock())
     harness.begin()
 
-    jenkins_charm: JenkinsAgentCharm = harness.charm
-    upgrade_charm_event = MagicMock(spec=ops.UpgradeCharmEvent)
-    jenkins_charm._on_upgrade_charm(upgrade_charm_event)
+    charm: JenkinsAgentCharm = harness.charm
+    charm.on.upgrade_charm.emit()
 
-    assert jenkins_charm.unit.status.message == "Waiting for relation."
-    assert jenkins_charm.unit.status.name == ops.BlockedStatus.name
+    assert charm.unit.status.message == "Waiting for relation."
+    assert charm.unit.status.name == ops.BlockedStatus.name
 
 
 def test__on_config_changed(harness: ops.testing.Harness, monkeypatch: pytest.MonkeyPatch):
@@ -73,12 +59,73 @@ def test__on_config_changed(harness: ops.testing.Harness, monkeypatch: pytest.Mo
     assert: The charm correctly updates the relation databag.
     """
     harness.begin()
-    config_changed_event = MagicMock(spec=ops.ConfigChangedEvent)
     get_relation_mock = MagicMock()
     monkeypatch.setattr(ops.Model, "get_relation", get_relation_mock)
 
-    jenkins_charm: JenkinsAgentCharm = harness.charm
-    jenkins_charm._on_config_changed(config_changed_event)
+    charm: JenkinsAgentCharm = harness.charm
+    charm.on.config_changed.emit()
 
     agent_relation = get_relation_mock.return_value
-    assert agent_relation.data[harness._unit_name].update.call_count == 1
+    assert agent_relation.data[charm.unit.name].update.call_count == 1
+
+
+def test_restart_agent_service(harness: ops.testing.Harness, monkeypatch: pytest.MonkeyPatch):
+    """
+    arrange: given a charm with patched relation.
+    act: when _on_config_changed is called.
+    assert: The charm correctly updates the relation databag.
+    """
+    get_relation_mock = MagicMock()
+    monkeypatch.setattr(ops.Model, "get_relation", get_relation_mock)
+    get_credentials_mock = MagicMock()
+    restart_mock = MagicMock()
+    monkeypatch.setattr(service.JenkinsAgentService, "restart", restart_mock)
+    harness.begin()
+
+    charm: JenkinsAgentCharm = harness.charm
+    monkeypatch.setattr(charm.state, "agent_relation_credentials", get_credentials_mock)
+    charm.restart_agent_service()
+
+    assert restart_mock.call_count == 1
+    assert charm.unit.status.name == ops.ActiveStatus.name
+
+
+def test_restart_agent_service_incomplete_relation_data(
+    harness: ops.testing.Harness, monkeypatch: pytest.MonkeyPatch
+):
+    """
+    arrange: given a charm with patched relation and incomplete relation data.
+    act: when restart_agent_service is called.
+    assert: The charm skips service restart and waits for complete relation data.
+    """
+    get_relation_mock = MagicMock()
+    monkeypatch.setattr(ops.Model, "get_relation", get_relation_mock)
+    harness.begin()
+
+    charm: JenkinsAgentCharm = harness.charm
+    monkeypatch.setattr(charm.state, "agent_relation_credentials", None)
+    charm.restart_agent_service()
+
+    assert charm.unit.status.name == ops.WaitingStatus.name
+
+
+def test_restart_agent_service_service_restart_error(
+    harness: ops.testing.Harness, monkeypatch: pytest.MonkeyPatch
+):
+    """
+    arrange: given a charm with patched relation and complete relation data.
+    act: when restart_agent_service is called, raising an error.
+    assert: The charm goes into error state with the correct error message.
+    """
+    get_relation_mock = MagicMock()
+    monkeypatch.setattr(ops.Model, "get_relation", get_relation_mock)
+    get_credentials_mock = MagicMock()
+    restart_mock = MagicMock(side_effect=service.ServiceRestartError)
+    monkeypatch.setattr(service.JenkinsAgentService, "restart", restart_mock)
+
+    harness.begin()
+
+    charm: JenkinsAgentCharm = harness.charm
+    monkeypatch.setattr(charm.state, "agent_relation_credentials", get_credentials_mock)
+    with pytest.raises(RuntimeError, match="Error restarting the agent service"):
+        charm.restart_agent_service()