[Upd] User states

packages/cache/src/sync.test.tsx

@@ -0,0 +1,19 @@
+import { describe, expect, it } from "vitest";
+
+import { removeMissingContactSnapshots } from "./sync";
+
+describe("authoritative contact cache updates", () => {
+  it("removes missing users and keeps the latest authoritative set", () => {
+    const contacts = [{ UserId: 2 }, { UserId: 3 }, { UserId: 4 }];
+    expect(removeMissingContactSnapshots(contacts, [3, 99])).toEqual([
+      { UserId: 2 },
+      { UserId: 4 },
+    ]);
+  });
+
+  it("does not let a delayed state notification recreate a removed contact", () => {
+    const contacts = [{ UserId: 2 }];
+    const afterMissing = removeMissingContactSnapshots(contacts, [2]);
+    expect(removeMissingContactSnapshots(afterMissing, [])).toEqual([]);
+  });
+});