feat(redis): limit the sidebar database list

apps/desktop/src/lib/__tests__/redis/redisDatabaseAlias.spec.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { normalizeRedisDatabaseAliases, redisDatabaseAlias, redisDatabaseLabel } from "@/lib/redis/redisDatabaseAlias";
+import { limitRedisDatabaseList, normalizeRedisDatabaseAliases, redisDatabaseAlias, redisDatabaseLabel, REDIS_DATABASE_DISPLAY_LIMIT_DEFAULT } from "@/lib/redis/redisDatabaseAlias";
 
 describe("redisDatabaseAlias", () => {
   it("normalizes numeric database keys and trims aliases", () => {
@@ -32,4 +32,22 @@ describe("redisDatabaseAlias", () => {
     expect(redisDatabaseLabel(0, undefined, 0)).toBe("db0 (0)");
     expect(redisDatabaseLabel(2, { "2": "cache" })).toBe("db2 · cache");
   });
+
+  it("leaves the list untouched when it fits within the limit", () => {
+    const items = [1, 2, 3];
+    expect(limitRedisDatabaseList(items, 10)).toEqual({ visible: items, hasMore: false });
+  });
+
+  it("truncates and reports more items are available", () => {
+    const items = [1, 2, 3, 4, 5];
+    expect(limitRedisDatabaseList(items, 2)).toEqual({ visible: [1, 2], hasMore: true });
+  });
+
+  it("falls back to the default limit for missing or invalid values (#1236)", () => {
+    const items = Array.from({ length: REDIS_DATABASE_DISPLAY_LIMIT_DEFAULT + 1 }, (_, i) => i);
+    expect(limitRedisDatabaseList(items, undefined).hasMore).toBe(true);
+    expect(limitRedisDatabaseList(items, 0).hasMore).toBe(true);
+    expect(limitRedisDatabaseList(items, -5).hasMore).toBe(true);
+    expect(limitRedisDatabaseList(items.slice(0, REDIS_DATABASE_DISPLAY_LIMIT_DEFAULT), undefined).hasMore).toBe(false);
+  });
 });