Add via parameter for MSC4156 (#4247)

* Add via parameter for MSC4156

Signed-off-by: Johannes Marbach <n0-0ne+github@mailbox.org>

* Always include both parameters

* Fix tests

---------

Signed-off-by: Johannes Marbach <n0-0ne+github@mailbox.org>

Author: Johennes

spec/integ/matrix-client-methods.spec.ts

@@ -257,7 +257,7 @@ describe("MatrixClient", function () {
                 .when("POST", "/knock/" + encodeURIComponent(roomId))
                 .check((request) => {
                     expect(request.data).toEqual({ reason: opts.reason });
-                    expect(request.queryParams).toEqual({ server_name: opts.viaServers });
+                    expect(request.queryParams).toEqual({ server_name: opts.viaServers, via: opts.viaServers });
                 })
                 .respond(200, { room_id: roomId });
 

src/client.ts

@@ -4319,9 +4319,13 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             signPromise = this.http.requestOtherUrl<IThirdPartySigned>(Method.Post, url);
         }
 
-        const queryString: Record<string, string | string[]> = {};
+        let queryParams: QueryDict = {};
         if (opts.viaServers) {
-            queryString["server_name"] = opts.viaServers;
+            queryParams.server_name = opts.viaServers;
+            queryParams.via = opts.viaServers;
+            if (this.canSupport.get(Feature.MigrateServerNameToVia) === ServerSupport.Unstable) {
+                queryParams = replaceParam("via", "org.matrix.msc4156.via", queryParams);
+            }
         }
 
         const data: IJoinRequestBody = {};
@@ -4331,7 +4335,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
 
         const path = utils.encodeUri("/join/$roomid", { $roomid: roomIdOrAlias });
-        const res = await this.http.authedRequest<{ room_id: string }>(Method.Post, path, queryString, data);
+        const res = await this.http.authedRequest<{ room_id: string }>(Method.Post, path, queryParams, data);
 
         const roomId = res.room_id;
         // In case we were originally given an alias, check the room cache again
@@ -4364,9 +4368,13 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
         const path = utils.encodeUri("/knock/$roomIdOrAlias", { $roomIdOrAlias: roomIdOrAlias });
 
-        const queryParams: Record<string, string | string[]> = {};
+        let queryParams: QueryDict = {};
         if (opts.viaServers) {
             queryParams.server_name = opts.viaServers;
+            queryParams.via = opts.viaServers;
+            if (this.canSupport.get(Feature.MigrateServerNameToVia) === ServerSupport.Unstable) {
+                queryParams = replaceParam("via", "org.matrix.msc4156.via", queryParams);
+            }
         }
 
         const body: Record<string, string> = {};

src/feature.ts

@@ -33,6 +33,7 @@ export enum Feature {
     AccountDataDeletion = "AccountDataDeletion",
     RelationsRecursion = "RelationsRecursion",
     IntentionalMentions = "IntentionalMentions",
+    MigrateServerNameToVia = "MigrateServerNameToVia",
 }
 
 type FeatureSupportCondition = {
@@ -65,6 +66,9 @@ const featureSupportResolver: Record<string, FeatureSupportCondition> = {
         unstablePrefixes: ["org.matrix.msc3952_intentional_mentions"],
         matrixVersion: "v1.7",
     },
+    [Feature.MigrateServerNameToVia]: {
+        unstablePrefixes: ["org.matrix.msc4156"],
+    },
 };
 
 export async function buildFeatureSupportMap(versions: IServerVersions): Promise<Map<Feature, ServerSupport>> {