Matrix: avoid redundant self id retries

extensions/matrix/src/matrix/direct-room.test.ts

@@ -0,0 +1,43 @@
+import { describe, expect, it, vi } from "vitest";
+import { inspectMatrixDirectRoomEvidence } from "./direct-room.js";
+import type { MatrixClient } from "./sdk.js";
+
+function createClient(overrides: Partial<MatrixClient> = {}): MatrixClient {
+  return {
+    getUserId: vi.fn(async () => "@bot:example.org"),
+    getJoinedRoomMembers: vi.fn(async () => ["@bot:example.org", "@alice:example.org"]),
+    getRoomStateEvent: vi.fn(async () => ({})),
+    ...overrides,
+  } as unknown as MatrixClient;
+}
+
+describe("inspectMatrixDirectRoomEvidence", () => {
+  it("does not retry getUserId when callers explicitly pass a missing self user", async () => {
+    const getUserId = vi.fn(async () => "@bot:example.org");
+    const client = createClient({ getUserId });
+
+    const result = await inspectMatrixDirectRoomEvidence({
+      client,
+      roomId: "!dm:example.org",
+      remoteUserId: "@alice:example.org",
+      selfUserId: null,
+    });
+
+    expect(getUserId).not.toHaveBeenCalled();
+    expect(result.strict).toBe(false);
+  });
+
+  it("resolves selfUserId when callers leave it undefined", async () => {
+    const getUserId = vi.fn(async () => "@bot:example.org");
+    const client = createClient({ getUserId });
+
+    const result = await inspectMatrixDirectRoomEvidence({
+      client,
+      roomId: "!dm:example.org",
+      remoteUserId: "@alice:example.org",
+    });
+
+    expect(getUserId).toHaveBeenCalledTimes(1);
+    expect(result.strict).toBe(true);
+  });
+});

extensions/matrix/src/matrix/direct-room.ts

@@ -75,8 +75,9 @@ export async function inspectMatrixDirectRoomEvidence(params: {
   selfUserId?: string | null;
 }): Promise<MatrixDirectRoomEvidence> {
   const selfUserId =
-    trimMaybeString(params.selfUserId) ??
-    trimMaybeString(await params.client.getUserId().catch(() => null));
+    params.selfUserId !== undefined
+      ? trimMaybeString(params.selfUserId)
+      : trimMaybeString(await params.client.getUserId().catch(() => null));
   const joinedMembers = await readJoinedMatrixMembers(params.client, params.roomId);
   const strict = isStrictDirectMembership({
     selfUserId,