[nexus] migrate test_srp_client_remove_host to Nexus (openthread#12946)

This commit migrates the SRP client host removal test from the
thread-cert Python-based framework to the Nexus framework.

The new C++ implementation in tests/nexus/test_srp_client_remove_host.cpp
covers the same scenarios as the original Python script:
- Successful registration of SRP host and services.
- Verification that ClearHostAndServices() does not immediately remove
  server-side state.
- Verification that RemoveHostAndServices(removeKey=False,
  sendUnregToServer=True) marks the host and services as deleted on the
  SRP server.
- Verification that RemoveHostAndServices(removeKey=True,
  sendUnregToServer=True) fully removes the host and service entries
  from the SRP server.

The original Python script test_srp_client_remove_host.py is removed
as its functionality is now fully covered by the Nexus test.

Author: jwhui

tests/nexus/CMakeLists.txt

@@ -407,6 +407,7 @@ ot_nexus_test(reed_address_solicit_rejected "core;nexus")
 ot_nexus_test(router_downgrade_on_sec_policy_change "core;nexus")
 ot_nexus_test(srp_auto_start "core;nexus")
 ot_nexus_test(srp_client_change_lease "core;nexus")
+ot_nexus_test(srp_client_remove_host "core;nexus")
 ot_nexus_test(srp_lease "core;nexus")
 ot_nexus_test(srp_many_services_mtu_check "core;nexus")
 ot_nexus_test(zero_len_external_route "core;nexus")

tests/nexus/test_srp_client_remove_host.cpp

@@ -0,0 +1,178 @@
+/*
+ *  Copyright (c) 2026, The OpenThread Authors.
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the copyright holder nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "platform/nexus_core.hpp"
+#include "platform/nexus_node.hpp"
+
+namespace ot {
+namespace Nexus {
+
+static const Srp::Server::Host *FindHost(Node &aServer, const char *aName)
+{
+    static constexpr uint16_t kNameStringSize = 400;
+
+    const Srp::Server::Host *host = nullptr;
+    String<kNameStringSize>  fullName;
+
+    fullName.Append("%s.%s", aName, aServer.Get<Srp::Server>().GetDomain());
+
+    while (true)
+    {
+        host = aServer.Get<Srp::Server>().GetNextHost(host);
+
+        if (host == nullptr)
+        {
+            break;
+        }
+
+        if (StringMatch(host->GetFullName(), fullName.AsCString()))
+        {
+            break;
+        }
+    }
+
+    return host;
+}
+
+void TestSrpClientRemoveHost(void)
+{
+    Core nexus;
+
+    Node &server = nexus.CreateNode();
+    Node &client = nexus.CreateNode();
+
+    server.SetName("server");
+    client.SetName("client");
+
+    Log("Step 0: Start the server and client devices.");
+
+    server.Form();
+    nexus.AdvanceTime(13000);
+    VerifyOrQuit(server.Get<Mle::Mle>().IsLeader());
+
+    client.Join(server);
+    nexus.AdvanceTime(200000);
+    VerifyOrQuit(client.Get<Mle::Mle>().IsRouter());
+
+    server.Get<Srp::Server>().SetEnabled(true);
+    client.Get<Srp::Client>().EnableAutoStartMode(nullptr, nullptr);
+    nexus.AdvanceTime(15000);
+
+    Log("Step 1: Register a single service and verify that it worked.");
+
+    SuccessOrQuit(client.Get<Srp::Client>().SetHostName("host"));
+
+    Ip6::Address         address;
+    Srp::Client::Service service;
+
+    SuccessOrQuit(address.FromString("2001::1"));
+    SuccessOrQuit(client.Get<Srp::Client>().SetHostAddresses(&address, 1));
+
+    service.mName          = "_srv._udp";
+    service.mInstanceName  = "ins";
+    service.mSubTypeLabels = nullptr;
+    service.mTxtEntries    = nullptr;
+    service.mNumTxtEntries = 0;
+    service.mPort          = 1977;
+    service.mPriority      = 0;
+    service.mWeight        = 0;
+    service.mLease         = 0;
+    service.mKeyLease      = 0;
+    SuccessOrQuit(service.Init());
+    SuccessOrQuit(client.Get<Srp::Client>().AddService(service));
+
+    nexus.AdvanceTime(2000);
+
+    VerifyOrQuit(client.Get<Srp::Client>().GetHostInfo().GetState() == Srp::Client::kRegistered);
+
+    const Srp::Server::Host *host = FindHost(server, "host");
+    VerifyOrQuit(host != nullptr);
+    VerifyOrQuit(!host->IsDeleted());
+
+    uint8_t             numAddresses;
+    const Ip6::Address *addresses = host->GetAddresses(numAddresses);
+    VerifyOrQuit(numAddresses == 1);
+    {
+        Ip6::Address expectedAddress;
+        SuccessOrQuit(expectedAddress.FromString("2001::1"));
+        VerifyOrQuit(addresses[0] == expectedAddress);
+    }
+
+    VerifyOrQuit(!host->GetServices().IsEmpty());
+    const Srp::Server::Service *serverService = host->GetServices().GetHead();
+    VerifyOrQuit(!serverService->IsDeleted());
+    VerifyOrQuit(serverService->GetPort() == 1977);
+
+    Log("Step 2: Clear the info on client, and verify that it is still present on server.");
+
+    client.Get<Srp::Client>().ClearHostAndServices();
+    nexus.AdvanceTime(2000);
+
+    VerifyOrQuit(client.Get<Srp::Client>().GetHostInfo().GetName() == nullptr);
+    VerifyOrQuit(FindHost(server, "host") != nullptr);
+
+    Log("Step 3: Set host name and request 'host remove' requiring update to server.");
+
+    SuccessOrQuit(client.Get<Srp::Client>().SetHostName("host"));
+    SuccessOrQuit(
+        client.Get<Srp::Client>().RemoveHostAndServices(/* aRemoveKeyLease */ false, /* aSendUnregToServer */ true));
+    nexus.AdvanceTime(2000);
+
+    VerifyOrQuit(client.Get<Srp::Client>().GetHostInfo().GetName() == nullptr);
+
+    host = FindHost(server, "host");
+    VerifyOrQuit(host != nullptr);
+    VerifyOrQuit(host->IsDeleted());
+    VerifyOrQuit(!host->GetServices().IsEmpty());
+    VerifyOrQuit(host->GetServices().GetHead()->IsDeleted());
+
+    Log("Step 4: Request 'host remove' with `remove_key`.");
+
+    SuccessOrQuit(client.Get<Srp::Client>().SetHostName("host"));
+    SuccessOrQuit(
+        client.Get<Srp::Client>().RemoveHostAndServices(/* aRemoveKeyLease */ true, /* aSendUnregToServer */ true));
+    nexus.AdvanceTime(2000);
+
+    VerifyOrQuit(client.Get<Srp::Client>().GetHostInfo().GetName() == nullptr);
+    VerifyOrQuit(FindHost(server, "host") == nullptr);
+
+    Log("Test passed successfully");
+}
+
+} // namespace Nexus
+} // namespace ot
+
+int main(void)
+{
+    ot::Nexus::TestSrpClientRemoveHost();
+    printf("All tests passed\n");
+    return 0;
+}