Updated unit tests for input models

tests/units/input_models/routing/test_isis.py

@@ -5,15 +5,18 @@
 
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Literal
 
 import pytest
 from pydantic import ValidationError
 
+from anta.input_models.routing.isis import ISISInstance, TunnelPath
 from anta.tests.routing.isis import VerifyISISSegmentRoutingAdjacencySegments, VerifyISISSegmentRoutingDataplane
 
 if TYPE_CHECKING:
-    from anta.input_models.routing.isis import ISISInstance
+    from ipaddress import IPv4Address
+
+    from anta.custom_types import Interface
 
 
 class TestVerifyISISSegmentRoutingAdjacencySegmentsInput:
@@ -68,3 +71,31 @@ def test_invalid(self, instances: list[ISISInstance]) -> None:
         """Test VerifyISISSegmentRoutingDataplane.Input invalid inputs."""
         with pytest.raises(ValidationError):
             VerifyISISSegmentRoutingDataplane.Input(instances=instances)
+
+
+class TestTunnelPath:
+    """Test anta.input_models.routing.isis.TestTunnelPath."""
+
+    # pylint: disable=too-few-public-methods
+
+    @pytest.mark.parametrize(
+        ("nexthop", "type", "interface", "tunnel_id", "expected"),
+        [
+            pytest.param("1.1.1.1", None, None, None, "Next-hop: 1.1.1.1", id="nexthop"),
+            pytest.param(None, "ip", None, None, "Type: ip", id="type"),
+            pytest.param(None, None, "Et1", None, "Interface: Ethernet1", id="interface"),
+            pytest.param(None, None, None, "TI-LFA", "TunnelID: TI-LFA", id="tunnel_id"),
+            pytest.param("1.1.1.1", "ip", "Et1", "TI-LFA", "Next-hop: 1.1.1.1 Type: ip Interface: Ethernet1 TunnelID: TI-LFA", id="all"),
+            pytest.param(None, None, None, None, "", id="None"),
+        ],
+    )
+    def test_valid__str__(
+        self,
+        nexthop: IPv4Address | None,
+        type: Literal["ip", "tunnel"] | None,  # noqa: A002
+        interface: Interface | None,
+        tunnel_id: Literal["TI-LFA", "ti-lfa", "unset"] | None,
+        expected: str,
+    ) -> None:
+        """Test TunnelPath __str__."""
+        assert str(TunnelPath(nexthop=nexthop, type=type, interface=interface, tunnel_id=tunnel_id)) == expected