diff --git a/n2vc/tests/unit/test_libjuju.py b/n2vc/tests/unit/test_libjuju.py
index 724b5d7..918a2fb 100644
--- a/n2vc/tests/unit/test_libjuju.py
+++ b/n2vc/tests/unit/test_libjuju.py
@@ -20,7 +20,12 @@
 import kubernetes
 from juju.errors import JujuAPIError
 import logging
-from .utils import FakeMachine, FakeApplication
+from .utils import (
+    FakeApplication,
+    FakeMachine,
+    FakeManualMachine,
+    FakeUnit,
+)
 from n2vc.libjuju import Libjuju
 from n2vc.exceptions import (
     JujuControllerFailedConnecting,
@@ -824,7 +829,7 @@
         mock_disconnect_controller.assert_called()
         mock_disconnect_model.assert_called()
 
-    def test_succesful_exec(
+    def test_successful_exec(
         self,
         mock_get_action_status,
         mock_get_action_output,
@@ -1966,7 +1971,7 @@
     def setUp(self):
         super(GetUnitNumberTest, self).setUp()
 
-    def test_succesful_get_unit_number(
+    def test_successful_get_unit_number(
         self,
         mock_get_applications,
     ):
@@ -1983,3 +1988,287 @@
         model = juju.model.Model()
         result = self.libjuju._get_application_count(model, "app")
         self.assertEqual(result, None)
+
+
+@asynctest.mock.patch("juju.model.Model.machines", new_callable=asynctest.PropertyMock)
+class GetMachineInfoTest(LibjujuTestCase):
+    def setUp(self):
+        super(GetMachineInfoTest, self).setUp()
+
+    def test_successful(
+        self,
+        mock_machines,
+    ):
+        machine_id = "existing_machine"
+        model = juju.model.Model()
+        mock_machines.return_value = {"existing_machine": FakeManualMachine()}
+        machine, series = self.libjuju._get_machine_info(
+            machine_id=machine_id,
+            model=model,
+        )
+        self.assertIsNotNone(machine, series)
+
+    def test_exception(
+        self,
+        mock_machines,
+    ):
+        machine_id = "not_existing_machine"
+        machine = series = None
+        model = juju.model.Model()
+        mock_machines.return_value = {"existing_machine": FakeManualMachine()}
+        with self.assertRaises(JujuMachineNotFound):
+            machine, series = self.libjuju._get_machine_info(
+                machine_id=machine_id,
+                model=model,
+            )
+        self.assertIsNone(machine, series)
+
+
+class GetUnitTest(LibjujuTestCase):
+    def setUp(self):
+        super(GetUnitTest, self).setUp()
+
+    def test_successful(self):
+        result = self.libjuju._get_unit(FakeApplication(), "existing_machine_id")
+        self.assertIsInstance(result, FakeUnit)
+
+    def test_return_none(self):
+        result = self.libjuju._get_unit(FakeApplication(), "not_existing_machine_id")
+        self.assertIsNone(result)
+
+
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.get_controller")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.get_model")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.disconnect_model")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.disconnect_controller")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju._get_application")
+class CheckApplicationExists(LibjujuTestCase):
+    def setUp(self):
+        super(CheckApplicationExists, self).setUp()
+
+    def test_successful(
+        self,
+        mock_get_application,
+        mock_disconnect_controller,
+        mock_disconnect_model,
+        mock_get_model,
+        mock_get_controller,
+    ):
+        mock_get_model.return_value = juju.model.Model()
+        mock_get_application.return_value = FakeApplication()
+        result = self.loop.run_until_complete(
+            self.libjuju.check_application_exists(
+                "model",
+                "app",
+            )
+        )
+        self.assertEqual(result, True)
+
+        mock_get_application.assert_called_once()
+        mock_get_controller.assert_called_once()
+        mock_get_model.assert_called_once()
+        mock_disconnect_controller.assert_called_once()
+        mock_disconnect_model.assert_called_once()
+
+    def test_no_application(
+        self,
+        mock_get_application,
+        mock_disconnect_controller,
+        mock_disconnect_model,
+        mock_get_model,
+        mock_get_controller,
+    ):
+        mock_get_model.return_value = juju.model.Model()
+        mock_get_application.return_value = None
+        result = self.loop.run_until_complete(
+            self.libjuju.check_application_exists(
+                "model",
+                "app",
+            )
+        )
+        self.assertEqual(result, False)
+
+        mock_get_application.assert_called_once()
+        mock_get_controller.assert_called_once()
+        mock_get_model.assert_called_once()
+        mock_disconnect_controller.assert_called_once()
+        mock_disconnect_model.assert_called_once()
+
+
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.get_controller")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.get_model")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.disconnect_model")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.disconnect_controller")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju._get_application")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju._get_machine_info")
+class AddUnitTest(LibjujuTestCase):
+    def setUp(self):
+        super(AddUnitTest, self).setUp()
+
+    @asynctest.mock.patch("n2vc.juju_watcher.JujuModelWatcher.wait_for")
+    @asynctest.mock.patch("asyncio.sleep")
+    def test_successful(
+        self,
+        mock_sleep,
+        mock_wait_for,
+        mock_get_machine_info,
+        mock_get_application,
+        mock_disconnect_controller,
+        mock_disconnect_model,
+        mock_get_model,
+        mock_get_controller,
+    ):
+        mock_get_model.return_value = juju.model.Model()
+        mock_get_application.return_value = FakeApplication()
+        mock_get_machine_info.return_value = FakeMachine(), "series"
+        self.loop.run_until_complete(
+            self.libjuju.add_unit(
+                "existing_app",
+                "model",
+                "machine",
+            )
+        )
+
+        mock_wait_for.assert_called_once()
+        mock_get_application.assert_called_once()
+        mock_get_controller.assert_called_once()
+        mock_get_model.assert_called_once()
+        mock_disconnect_controller.assert_called_once()
+        mock_disconnect_model.assert_called_once()
+
+    def test_no_app(
+        self,
+        mock_get_machine_info,
+        mock_get_application,
+        mock_disconnect_controller,
+        mock_disconnect_model,
+        mock_get_model,
+        mock_get_controller,
+    ):
+        mock_get_model.return_value = juju.model.Model()
+        mock_get_application.return_value = None
+        with self.assertRaises(JujuApplicationNotFound):
+            self.loop.run_until_complete(
+                self.libjuju.add_unit(
+                    "existing_app",
+                    "model",
+                    "machine",
+                )
+            )
+
+        mock_get_application.assert_called_once()
+        mock_get_controller.assert_called_once()
+        mock_get_model.assert_called_once()
+        mock_disconnect_controller.assert_called_once()
+        mock_disconnect_model.assert_called_once()
+
+    def test_no_machine(
+        self,
+        mock_get_machine_info,
+        mock_get_application,
+        mock_disconnect_controller,
+        mock_disconnect_model,
+        mock_get_model,
+        mock_get_controller,
+    ):
+        mock_get_model.return_value = juju.model.Model()
+        mock_get_application.return_value = FakeApplication()
+        mock_get_machine_info.side_effect = JujuMachineNotFound()
+        with self.assertRaises(JujuMachineNotFound):
+            self.loop.run_until_complete(
+                self.libjuju.add_unit(
+                    "existing_app",
+                    "model",
+                    "machine",
+                )
+            )
+
+        mock_get_application.assert_called_once()
+        mock_get_controller.assert_called_once()
+        mock_get_model.assert_called_once()
+        mock_disconnect_controller.assert_called_once()
+        mock_disconnect_model.assert_called_once()
+
+
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.get_controller")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.get_model")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.disconnect_model")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju.disconnect_controller")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju._get_application")
+@asynctest.mock.patch("n2vc.libjuju.Libjuju._get_unit")
+class DestroyUnitTest(LibjujuTestCase):
+    def setUp(self):
+        super(DestroyUnitTest, self).setUp()
+
+    @asynctest.mock.patch("asyncio.sleep")
+    def test_successful(
+        self,
+        mock_sleep,
+        mock_get_unit,
+        mock_get_application,
+        mock_disconnect_controller,
+        mock_disconnect_model,
+        mock_get_model,
+        mock_get_controller,
+    ):
+        mock_get_model.return_value = juju.model.Model()
+        mock_get_application.return_value = FakeApplication()
+
+        self.loop.run_until_complete(
+            self.libjuju.destroy_unit("app", "model", "machine", 0)
+        )
+
+        mock_get_unit.assert_called()
+        mock_get_application.assert_called_once()
+        mock_get_controller.assert_called_once()
+        mock_get_model.assert_called_once()
+        mock_disconnect_controller.assert_called_once()
+        mock_disconnect_model.assert_called_once()
+
+    def test_no_app(
+        self,
+        mock_get_unit,
+        mock_get_application,
+        mock_disconnect_controller,
+        mock_disconnect_model,
+        mock_get_model,
+        mock_get_controller,
+    ):
+        mock_get_model.return_value = juju.model.Model()
+        mock_get_application.return_value = None
+
+        with self.assertRaises(JujuApplicationNotFound):
+            self.loop.run_until_complete(
+                self.libjuju.destroy_unit("app", "model", "machine")
+            )
+
+        mock_get_application.assert_called_once()
+        mock_get_controller.assert_called_once()
+        mock_get_model.assert_called_once()
+        mock_disconnect_controller.assert_called_once()
+        mock_disconnect_model.assert_called_once()
+
+    def test_no_unit(
+        self,
+        mock_get_unit,
+        mock_get_application,
+        mock_disconnect_controller,
+        mock_disconnect_model,
+        mock_get_model,
+        mock_get_controller,
+    ):
+        mock_get_model.return_value = juju.model.Model()
+        mock_get_application.return_value = FakeApplication()
+        mock_get_unit.return_value = None
+
+        with self.assertRaises(JujuError):
+            self.loop.run_until_complete(
+                self.libjuju.destroy_unit("app", "model", "machine")
+            )
+
+        mock_get_unit.assert_called_once()
+        mock_get_application.assert_called_once()
+        mock_get_controller.assert_called_once()
+        mock_get_model.assert_called_once()
+        mock_disconnect_controller.assert_called_once()
+        mock_disconnect_model.assert_called_once()
diff --git a/n2vc/tests/unit/utils.py b/n2vc/tests/unit/utils.py
index 7e8907f..b2d5c60 100644
--- a/n2vc/tests/unit/utils.py
+++ b/n2vc/tests/unit/utils.py
@@ -123,6 +123,7 @@
     model_name = "FAKE MODEL"
     entity_type = "machine"
     safe_data = {"instance-id": "manual:myid"}
+    series = "FAKE SERIES"
 
     async def destroy(self, force):
         pass
@@ -162,6 +163,12 @@
     async def run_action(self, action_name, **kwargs):
         return FakeAction()
 
+    @property
+    def machine_id(self):
+        return "existing_machine_id"
+
+    name = "existing_unit"
+
 
 class FakeApplication(AsyncMock):
     async def set_config(self, config):
@@ -170,6 +177,9 @@
     async def add_unit(self, to):
         pass
 
+    async def destroy_unit(self, unit_name):
+        pass
+
     async def get_actions(self):
         return ["existing_action"]