From c4777bed39a0567e9d3cb4d801348acaa4de5351 Mon Sep 17 00:00:00 2001
From: Eric Eastwood <erice@element.io>
Date: Wed, 10 Dec 2025 17:15:24 -0600
Subject: [PATCH 1/2] Non-working: Test fake homeserver is contactable from
 host-side

> Perhaps the fake homeserver that Complement is mocking isn't running
> properly. As a sanity check, we could send a request on the host-side to
> the fake server that's also on the host-side that we expect to be
> responding.
---
 federation/handle.go               | 20 ++++++++++++++++++++
 tests/federation_room_join_test.go | 18 ++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/federation/handle.go b/federation/handle.go
index eaaba9b7..a91c8cd0 100644
--- a/federation/handle.go
+++ b/federation/handle.go
@@ -15,6 +15,26 @@ import (
 	"github.com/matrix-org/util"
 )
 
+// HandleVersionRequests is an option which makes the server process `/_matrix/federation/v1/version` requests.
+func HandleVersionRequests() func(*Server) {
+	return func(srv *Server) {
+		mux := srv.mux.PathPrefix("/_matrix/federation/v1").Subrouter()
+
+		handlerFn := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+			w.WriteHeader(200)
+			b, _ := json.Marshal(map[string]interface{}{
+				"server": map[string]interface{}{
+					"name":    "complement-federation-test-server",
+					"version": "0.1.0",
+				},
+			})
+			w.Write(b)
+		})
+
+		mux.Handle("/version", handlerFn).Methods("GET")
+	}
+}
+
 // EXPERIMENTAL
 // MakeJoinRequestsHandler is the http.Handler implementation for the make_join part of
 // HandleMakeSendJoinRequests.
diff --git a/tests/federation_room_join_test.go b/tests/federation_room_join_test.go
index 03b12ee0..bf67799b 100644
--- a/tests/federation_room_join_test.go
+++ b/tests/federation_room_join_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"net/url"
 	"strings"
@@ -24,6 +25,7 @@ import (
 	"github.com/matrix-org/complement/client"
 	"github.com/matrix-org/complement/federation"
 	"github.com/matrix-org/complement/helpers"
+	"github.com/matrix-org/complement/internal"
 	"github.com/matrix-org/complement/match"
 	"github.com/matrix-org/complement/must"
 	"github.com/matrix-org/complement/runtime"
@@ -296,12 +298,17 @@ func TestJoinFederatedRoomWithUnverifiableEvents(t *testing.T) {
 	})
 }
 
+func VersionRequestHandler(s *federation.Server, w http.ResponseWriter, req *http.Request) {
+	// Send it
+}
+
 // This test checks that users cannot circumvent the auth checks via send_join.
 func TestBannedUserCannotSendJoin(t *testing.T) {
 	deployment := complement.Deploy(t, 1)
 	defer deployment.Destroy(t)
 
 	srv := federation.NewServer(t, deployment,
+		federation.HandleVersionRequests(),
 		federation.HandleKeyRequests(),
 		federation.HandleTransactionRequests(nil, nil),
 	)
@@ -309,6 +316,17 @@ func TestBannedUserCannotSendJoin(t *testing.T) {
 	origin := srv.ServerName()
 	defer cancel()
 
+	// XXX: Sanity check that the server is listening and responding (at-least from the host perspective)
+	splitPieces := strings.SplitN(string(srv.ServerName()), ":", 2)
+	port := splitPieces[1]
+	res, err := http.Get("https://localhost:" + port + "/_matrix/federation/v1/version")
+	if err != nil {
+		t.Fatalf("Failed to GET: %s", err)
+	}
+	defer internal.CloseIO(res.Body, "server response body")
+	resBody, err := io.ReadAll(res.Body)
+	t.Logf("asdf request %d %s", res.StatusCode, resBody)
+
 	fedClient := srv.FederationClient(deployment)
 
 	charlie := srv.UserID("charlie")

From 772ec93516adf5a21e1938cd063cbffd1f1e2615 Mon Sep 17 00:00:00 2001
From: Eric Eastwood <erice@element.io>
Date: Wed, 10 Dec 2025 17:59:19 -0600
Subject: [PATCH 2/2] Working request

---
 tests/federation_room_join_test.go | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tests/federation_room_join_test.go b/tests/federation_room_join_test.go
index bf67799b..34735679 100644
--- a/tests/federation_room_join_test.go
+++ b/tests/federation_room_join_test.go
@@ -2,6 +2,7 @@ package tests
 
 import (
 	"context"
+	"crypto/tls"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -319,7 +320,13 @@ func TestBannedUserCannotSendJoin(t *testing.T) {
 	// XXX: Sanity check that the server is listening and responding (at-least from the host perspective)
 	splitPieces := strings.SplitN(string(srv.ServerName()), ":", 2)
 	port := splitPieces[1]
-	res, err := http.Get("https://localhost:" + port + "/_matrix/federation/v1/version")
+	// Ignore HTTPS/TLS verification for localhost
+	httpTransport := &http.Transport{
+		TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
+	}
+	httpClient := &http.Client{Transport: httpTransport}
+	// Make the request
+	res, err := httpClient.Get("https://localhost:" + port + "/_matrix/federation/v1/version")
 	if err != nil {
 		t.Fatalf("Failed to GET: %s", err)
 	}