test: simplify interfaces/veth_delete

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/case/interfaces/veth_delete/test.adoc

@@ -23,8 +23,7 @@ image::topology.svg[Verify that VETH Pairs Can Be Deleted topology, align=center
 . Verify interfaces 'veth0a' and 'veth0b' exist
 . Set IP address on target:data1 (dummy op)
 . Set IP address on target:data2 (dummy op)
-. Reset configuration
-. Verify target:data1 and target:data2 still exist
-. Verify VETH pair have been removed
+. Delete VETH pair
+. Verify VETH pair has been removed
 
 

test/case/interfaces/veth_delete/test.py

@@ -86,23 +86,15 @@ with infamy.Test() as test:
             }
         }})
 
-    # TODO: need target.del_config_dict() or similar for VETH _pairs_,
-    #       because both interfaces must be removed at the same time.
-    # with test.step("Delete VETH pair"):
-    #     xpath = f"/ietf-interfaces:interfaces/interface[name='{veth0a}']"
-    #     target.delete_xpath(xpath)
-    # XXX: temporary workaround
-    with test.step("Reset configuration"):
-        # Calls target.test_reset() to apply safe-config
-        target = env.attach("target", "mgmt")
+    with test.step("Delete VETH pair"):
+        # Both ends are mutually mandatory leafrefs, so they must be
+        # removed in a single transaction.
+        target.delete_xpaths([
+            f"/ietf-interfaces:interfaces/interface[name='{veth0a}']",
+            f"/ietf-interfaces:interfaces/interface[name='{veth0b}']",
+        ])
 
-    with test.step("Verify target:data1 and target:data2 still exist"):
-        assert iface.exist(target, data1), \
-            f"Interface {data1} missing!"
-        assert iface.exist(target, data2), \
-            f"Interface {data2} missing!"
-
-    with test.step("Verify VETH pair have been removed"):
+    with test.step("Verify VETH pair has been removed"):
         assert not iface.exist(target, veth0a), \
             f"Interface <{veth0a}> still exists!"
         assert not iface.exist(target, veth0b), \