(feat): add cache package

(feat): improve local storage security
(feat): move settings to dedicated settings package

packages/cache/src/helpers.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, it } from "vitest";
+import {
+  replaceConversation,
+  selectConversationWindows,
+  trimMessages,
+} from "./helpers";
+import type { CachedMessage, ConversationWindow } from "./schemas";
+
+const message = (SendTime: number): CachedMessage => ({
+  SenderId: 1,
+  SendTime,
+  Content: "Y2lwaGVydGV4dA==",
+  MessageState: "received",
+});
+const window = (UserId: number, LastMessageAt: number): ConversationWindow => ({
+  UserId,
+  LastMessageAt,
+  Messages: [],
+});
+
+describe("conversation cache helpers", () => {
+  it("selects the five most recent windows", () => {
+    const selected = selectConversationWindows(
+      [
+        window(1, 1),
+        window(2, 6),
+        window(3, 3),
+        window(4, 4),
+        window(5, 5),
+        window(6, 2),
+      ],
+      5,
+    );
+    expect(selected.map(({ UserId }) => UserId)).toEqual([2, 5, 4, 3, 6]);
+  });
+
+  it("replaces only the matching conversation", () => {
+    expect(
+      replaceConversation([window(1, 1), window(2, 2)], window(1, 9)),
+    ).toEqual([window(1, 9), window(2, 2)]);
+  });
+
+  it("retains the newest messages in chronological order", () => {
+    expect(
+      trimMessages([message(2), message(3), message(1)], 2).map(
+        (item) => item.SendTime,
+      ),
+    ).toEqual([2, 3]);
+  });
+});