From 7ab71d45c08bc67c7d0166df4879a781bec25f5a Mon Sep 17 00:00:00 2001
From: Eric Eastwood <erice@element.io>
Date: Sat, 6 Nov 2021 00:30:07 -0500
Subject: [PATCH] Make sure historical events aren't sent as AS transactions

Regression tests for https://github.com/matrix-org/synapse/issues/11241

Synapse changes: https://github.com/matrix-org/synapse/pull/11265
---
 internal/b/hs_with_application_service.go |  2 +-
 tests/msc2716_test.go                     | 98 +++++++++++++++++++++++
 2 files changed, 99 insertions(+), 1 deletion(-)

diff --git a/internal/b/hs_with_application_service.go b/internal/b/hs_with_application_service.go
index e3aa059b..fe20baf0 100644
--- a/internal/b/hs_with_application_service.go
+++ b/internal/b/hs_with_application_service.go
@@ -15,7 +15,7 @@ var BlueprintHSWithApplicationService = MustValidate(Blueprint{
 			ApplicationServices: []ApplicationService{
 				{
 					ID:              "my_as_id",
-					URL:             "http://localhost:9000",
+					URL:             "http://host.docker.internal:9111",
 					SenderLocalpart: "the-bridge-user",
 					RateLimited:     false,
 				},
diff --git a/tests/msc2716_test.go b/tests/msc2716_test.go
index 971b5e0e..69d5adab 100644
--- a/tests/msc2716_test.go
+++ b/tests/msc2716_test.go
@@ -8,6 +8,7 @@ package tests
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -15,6 +16,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/gorilla/mux"
 	"github.com/tidwall/gjson"
 
 	"github.com/matrix-org/complement/internal/b"
@@ -307,6 +309,102 @@ func TestImportHistoricalMessages(t *testing.T) {
 			})
 		})
 
+		t.Run("Historical events from batch_send do not get pushed out as application service transactions", func(t *testing.T) {
+			t.Parallel()
+
+			// Create a listener and handler to stub an application service listening
+			// for transactions from a homeserver.
+			handler := mux.NewRouter()
+			// Application Service API: /_matrix/app/v1/transactions/{txnId}
+			waiter := NewWaiter()
+			var eventIDsWeSawOverTransactions []string
+			var eventIDAfterHistoricalImport string
+			handler.HandleFunc("/transactions/{txnId}", func(w http.ResponseWriter, req *http.Request) {
+				must.MatchRequest(t, req, match.HTTPRequest{
+					JSON: []match.JSON{
+						match.JSONArrayEach("events", func(r gjson.Result) error {
+							// Add to our running list of events
+							eventIDsWeSawOverTransactions = append(eventIDsWeSawOverTransactions, r.Get("event_id").Str)
+
+							// If we found the event that occurs after our batch send. we can
+							// probably safely assume the historical events won't come later.
+							if r.Get("event_id").Str != "" && r.Get("event_id").Str == eventIDAfterHistoricalImport {
+								defer waiter.Finish()
+							}
+
+							return nil
+						}),
+					},
+				})
+
+				// Acknowledge that we've seen the transaction
+				w.WriteHeader(200)
+				w.Write([]byte("{}"))
+			}).Methods("PUT")
+
+			srv := &http.Server{
+				Addr:    ":9111",
+				Handler: handler,
+			}
+			go func() {
+				srv.ListenAndServe()
+			}()
+			defer srv.Shutdown(context.Background())
+			// ----------------------------------------------------------
+
+			// Create the room all of the action is going to happen in
+			roomID := as.CreateRoom(t, createPublicRoomOpts)
+			alice.JoinRoom(t, roomID, nil)
+
+			// Create the "live" event we are going to insert our historical events next to
+			eventIDsBefore := createMessagesInRoom(t, alice, roomID, 1)
+			eventIdBefore := eventIDsBefore[0]
+			timeAfterEventBefore := time.Now()
+
+			// Import a historical event
+			batchSendRes := batchSendHistoricalMessages(
+				t,
+				as,
+				roomID,
+				eventIdBefore,
+				"",
+				createJoinStateEventsForBatchSendRequest([]string{virtualUserID}, timeAfterEventBefore),
+				createMessageEventsForBatchSendRequest([]string{virtualUserID}, timeAfterEventBefore, 1),
+				// Status
+				200,
+			)
+			batchSendResBody := client.ParseJSON(t, batchSendRes)
+			historicalEventIDs := client.GetJSONFieldStringArray(t, batchSendResBody, "event_ids")
+			historicalStateEventIDs := client.GetJSONFieldStringArray(t, batchSendResBody, "state_event_ids")
+
+			// This is just a dummy event we search for after the historicalEventIDs/historicalStateEventIDs
+			eventIDsAfterHistoricalImport := createMessagesInRoom(t, alice, roomID, 1)
+			eventIDAfterHistoricalImport = eventIDsAfterHistoricalImport[0]
+
+			// Check if eventIDAfterHistoricalImport already came over `/transactions`.
+			if !includes(eventIDAfterHistoricalImport, eventIDsWeSawOverTransactions) {
+				// If not, wait 5 seconds for to see if it happens. The waiter will only
+				// resolve if we see eventIDAfterHistoricalImport, otherwise timeout
+				waiter.Wait(t, 5*time.Second)
+			}
+
+			// Now, that we know eventIDAfterHistoricalImport came over /transactions,
+			// we can probably safely assume the historical events won't come later.
+
+			// Check to make sure the historical events didn't come over /transactions
+			for _, historicalEventID := range historicalEventIDs {
+				if includes(historicalEventID, eventIDsWeSawOverTransactions) {
+					t.Fatalf("We should not see the %s historical event come over /transactions but it did", historicalEventID)
+				}
+			}
+			// Check to make sure the historical state events didn't come over /transactions
+			for _, historicalStateEventID := range historicalStateEventIDs {
+				if includes(historicalStateEventID, eventIDsWeSawOverTransactions) {
+					t.Fatalf("We should not see the %s historical state event come over /transactions but it did", historicalStateEventID)
+				}
+			}
+		})
+
 		t.Run("Batch send endpoint only returns state events that we passed in via state_events_at_start", func(t *testing.T) {
 			t.Parallel()