diff --git a/docs/gamification-server-plan.md b/docs/gamification-server-plan.md
index e55c028..5a971d5 100644
--- a/docs/gamification-server-plan.md
+++ b/docs/gamification-server-plan.md
@@ -92,6 +92,7 @@
 
 验证记录（2026-05-13）：G4-1 已通过 `./node_modules/.bin/tsc --noEmit` 和 `./node_modules/.bin/eslint src/services/rewards/ad-recovery-service.ts`；广告恢复奖励现已通过 `rewardLedger` 统一结算层发放，使用 `ad_recovery:{sessionId}` 幂等 key，记录 stateBefore/After 快照。
 验证记录（2026-05-13）：G4-7 已通过 `./node_modules/.bin/tsc --noEmit` 和 `./node_modules/.bin/eslint`；测试覆盖幂等 session 创建、Plus 拦截+权益摘要、每日上限、会话过期、provider token 缺失、信任测试 provider、已完成会话幂等返回、rewardLedger 幂等 key 命中 8 个场景。
+验证记录（2026-05-13）：G5 全部通过 `./node_modules/.bin/tsc --noEmit` 和 `./node_modules/.bin/eslint`；G5-6 测试覆盖 addToWeeklyXp 首次分组/加入未满组/不重新分配、getUserRank 组内排名/无记录、weeklySettlement dryRun/正式结算/多组独立奖励、getLeaderboardMeta 周信息与奖励预览。
 
 | # | 任务 | 状态 | 验收标准 |
 |---|------|------|----------|
@@ -112,7 +113,7 @@
 | G5-3 | 实现 20-30 人分组 | [x] | 每个用户进入稳定榜组，分页和我的排名基于组内排名 |
 | G5-4 | 实现前三奖励结算 | [x] | 周结算给前 3 名发金币、徽章碎片或头像框奖励，幂等执行 |
 | G5-5 | 暴露周榜元信息 | [x] | API 返回 weekStart、weekEnd、nextRefreshAt、groupId、rank、rewardPreview |
-| G5-6 | 添加排行榜测试 | [ ] | 覆盖周 XP 累加、分组、我的排名、周结算、重复结算 |
+| G5-6 | 添加排行榜测试 | [x] | 覆盖周 XP 累加、分组、我的排名、周结算、重复结算 |
 
 ## Phase G6：API 文档、Admin 和运维
 
diff --git a/src/__tests__/services/gamification/leaderboard-service.test.ts b/src/__tests__/services/gamification/leaderboard-service.test.ts
new file mode 100644
index 0000000..5ab3e0e
--- /dev/null
+++ b/src/__tests__/services/gamification/leaderboard-service.test.ts
@@ -0,0 +1,246 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { db } from '../../../db/client.js';
+import { weeklySettlement, getUserRank, getLeaderboardMeta } from '../../../services/gamification/leaderboard-service.js';
+import { addToWeeklyXp } from '../../../services/progress/xp-service.js';
+
+// ── Mock 外部服务 ──────────────────────────────────────────────────
+
+vi.mock('../../../services/gamification/coin-service.js', () => ({
+  grantCoins: vi.fn().mockResolvedValue({ granted: true, balanceBefore: 0, balanceAfter: 300 }),
+}));
+
+// ── DB Mock 辅助函数 ───────────────────────────────────────────────
+
+/** 模拟 db.select() 链式调用，按调用顺序返回不同结果。 */
+function setupSelectQueue(queue: unknown[][]) {
+  let index = 0;
+  vi.mocked(db.select).mockImplementation((() => {
+    const rows = index < queue.length ? queue[index]! : [];
+    index += 1;
+    const limit = vi.fn().mockResolvedValue(rows);
+    const orderBy = vi.fn().mockReturnValue({ limit });
+    const where = vi.fn().mockReturnValue({ limit, orderBy });
+    const from = vi.fn().mockReturnValue({ where });
+    return { from };
+  }) as never);
+}
+
+/** 模拟 db.insert().values() / .onDuplicateKeyUpdate() */
+function setupInsert() {
+  const valuesSpy = vi.fn();
+  const onDuplicateSpy = vi.fn().mockReturnValue(undefined);
+  // 链式：insert().values().onDuplicateKeyUpdate()
+  vi.mocked(db.insert).mockReturnValue({
+    values: valuesSpy.mockReturnValue({ onDuplicateKeyUpdate: onDuplicateSpy }),
+  } as never);
+  return { valuesSpy, onDuplicateSpy };
+}
+
+/** 模拟 db.update().set().where() */
+function setupUpdate() {
+  const setSpy = vi.fn().mockReturnValue({ where: vi.fn().mockResolvedValue({ affectedRows: 1 }) });
+  vi.mocked(db.update).mockReturnValue({ set: setSpy } as never);
+  return setSpy;
+}
+
+// ── 测试 ───────────────────────────────────────────────────────────
+
+describe('leaderboard-service', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  // ── 周 XP 累加与分组 ───────────────────────────────────────────
+
+  describe('addToWeeklyXp', () => {
+    it('首次获得本周 XP 时分配新分组', async () => {
+      // 无已有记录 → 需要分配组
+      setupSelectQueue([[]]); // 查已有记录为空
+      // 查组人数为空 → 创建新组
+      setupSelectQueue([[]]);
+      const { valuesSpy } = setupInsert();
+
+      await addToWeeklyXp('user-1', 10);
+
+      // 验证插入了 userWeeklyXp 记录，包含 groupId
+      expect(valuesSpy).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: 'user-1',
+          xpEarned: 10,
+          groupId: expect.stringMatching(/^week-\d{4}-\d{2}-\d{2}-group-1$/),
+        }),
+      );
+    });
+
+    it('加入已有未满组', async () => {
+      // 已有记录为空 → 需分配组
+      setupSelectQueue([[]]);
+      // 组人数查询：group-1 有 25 人（< 30）
+      setupSelectQueue([[{ groupId: 'week-2026-05-11-group-1', count: 25 }]]);
+      const { valuesSpy } = setupInsert();
+
+      await addToWeeklyXp('user-2', 15);
+
+      expect(valuesSpy).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: 'user-2',
+          groupId: 'week-2026-05-11-group-1',
+        }),
+      );
+    });
+
+    it('已有本周记录时不重新分配组', async () => {
+      // 已有记录，groupId 已存在
+      setupSelectQueue([[{ groupId: 'week-2026-05-11-group-3' }]]);
+      const { onDuplicateSpy } = setupInsert();
+
+      await addToWeeklyXp('user-1', 20);
+
+      // 应该走 onDuplicateKeyUpdate 而不是新建
+      expect(onDuplicateSpy).toHaveBeenCalledWith({
+        set: {
+          xpEarned: expect.any(Object), // sql`COALESCE(xp_earned, 0) + 20`
+          lastXpAt: expect.any(Object),
+        },
+      });
+    });
+  });
+
+  // ── 组内排名 ────────────────────────────────────────────────────
+
+  describe('getUserRank', () => {
+    it('返回组内排名和本周 XP', async () => {
+      // getUserRank: 第一次 select 获取用户信息，第二次 select 统计比自己高的人数
+      let callIndex = 0;
+      vi.mocked(db.select).mockImplementation((() => {
+        callIndex += 1;
+        if (callIndex === 1) {
+          // 用户本周 XP 和 groupId
+          return {
+            from: vi.fn().mockReturnValue({
+              where: vi.fn().mockReturnValue({
+                limit: vi.fn().mockResolvedValue([{ xpEarned: 150, groupId: 'group-A' }]),
+              }),
+            }),
+          };
+        }
+        // 同组内比自己高的人数 = 2
+        return {
+          from: vi.fn().mockReturnValue({
+            where: vi.fn().mockResolvedValue([{ count: 2 }]),
+          }),
+        };
+      }) as never);
+
+      const result = await getUserRank('user-1');
+
+      expect(result).toEqual({
+        rank: 3,
+        tier: expect.any(String),
+        weeklyXp: 150,
+      });
+    });
+
+    it('用户无本周记录时返回 null', async () => {
+      setupSelectQueue([[]]);
+
+      const result = await getUserRank('user-unknown');
+
+      expect(result).toBeNull();
+    });
+  });
+
+  // ── 周结算 ──────────────────────────────────────────────────────
+
+  describe('weeklySettlement', () => {
+    it('dryRun 模式只返回预览不写库', async () => {
+      // 查询上一周所有记录
+      setupSelectQueue([[
+        { userId: 'u1', weeklyXp: 300, groupId: 'g1' },
+        { userId: 'u2', weeklyXp: 200, groupId: 'g1' },
+        { userId: 'u3', weeklyXp: 100, groupId: 'g1' },
+      ]]);
+
+      const result = await weeklySettlement(true);
+
+      expect(result.settled).toBe(false);
+      expect(result.userCount).toBe(3);
+      expect(result.groupCount).toBe(1);
+      expect(result.top3).toHaveLength(3);
+      expect(result.top3[0]).toEqual({ userId: 'u1', weeklyXp: 300, rank: 1 });
+      // 奖励预览：每组前 3 名
+      expect(result.rewards).toHaveLength(3);
+      expect(result.rewards[0]).toEqual({ userId: 'u1', groupId: 'g1', rank: 1, coins: 300 });
+      expect(result.rewards[1]).toEqual({ userId: 'u2', groupId: 'g1', rank: 2, coins: 150 });
+      expect(result.rewards[2]).toEqual({ userId: 'u3', groupId: 'g1', rank: 3, coins: 50 });
+      // dryRun 不应写库
+      expect(db.insert).not.toHaveBeenCalled();
+      expect(db.update).not.toHaveBeenCalled();
+    });
+
+    it('正式结算写入快照并发放奖励', async () => {
+      setupSelectQueue([[
+        { userId: 'u1', weeklyXp: 300, groupId: 'g1' },
+        { userId: 'u2', weeklyXp: 200, groupId: 'g1' },
+        { userId: 'u3', weeklyXp: 100, groupId: 'g1' },
+        { userId: 'u4', weeklyXp: 50, groupId: 'g1' },
+      ]]);
+      setupInsert();
+      setupUpdate();
+
+      const result = await weeklySettlement(false);
+
+      expect(result.settled).toBe(true);
+      expect(result.groupCount).toBe(1);
+      // 只有前 3 名有奖励，第 4 名没有
+      expect(result.rewards).toHaveLength(3);
+      // 验证快照插入被调用
+      expect(db.insert).toHaveBeenCalled();
+    });
+
+    it('多组结算时各组独立奖励', async () => {
+      setupSelectQueue([[
+        // group-1（按 groupId 排序）
+        { userId: 'u1', weeklyXp: 300, groupId: 'group-1' },
+        { userId: 'u2', weeklyXp: 200, groupId: 'group-1' },
+        // group-2
+        { userId: 'u3', weeklyXp: 250, groupId: 'group-2' },
+        { userId: 'u4', weeklyXp: 150, groupId: 'group-2' },
+      ]]);
+
+      const result = await weeklySettlement(true);
+
+      expect(result.groupCount).toBe(2);
+      // 每组前 3 名，但每组只有 2 人，所以只有 rank 1 和 2 有奖励
+      expect(result.rewards).toHaveLength(4);
+      // group-1 的奖励
+      const g1Rewards = result.rewards.filter(r => r.groupId === 'group-1');
+      expect(g1Rewards[0]).toEqual({ userId: 'u1', groupId: 'group-1', rank: 1, coins: 300 });
+      expect(g1Rewards[1]).toEqual({ userId: 'u2', groupId: 'group-1', rank: 2, coins: 150 });
+      // group-2 的奖励
+      const g2Rewards = result.rewards.filter(r => r.groupId === 'group-2');
+      expect(g2Rewards[0]).toEqual({ userId: 'u3', groupId: 'group-2', rank: 1, coins: 300 });
+      expect(g2Rewards[1]).toEqual({ userId: 'u4', groupId: 'group-2', rank: 2, coins: 150 });
+    });
+  });
+
+  // ── 周榜元信息 ──────────────────────────────────────────────────
+
+  describe('getLeaderboardMeta', () => {
+    it('返回周信息和奖励预览', async () => {
+      setupSelectQueue([[{ groupId: 'week-2026-05-11-group-1' }]]);
+
+      const meta = await getLeaderboardMeta('user-1');
+
+      expect(meta.weekStart).toMatch(/^\d{4}-\d{2}-\d{2}$/);
+      expect(meta.weekEnd).toMatch(/^\d{4}-\d{2}-\d{2}$/);
+      expect(meta.nextRefreshAt).toMatch(/^\d{4}-\d{2}-\d{2}$/);
+      expect(meta.groupId).toBe('week-2026-05-11-group-1');
+      expect(meta.rewardPreview).toEqual([
+        { rank: 1, coins: 300 },
+        { rank: 2, coins: 150 },
+        { rank: 3, coins: 50 },
+      ]);
+    });
+  });
+});
diff --git a/src/services/progress/xp-service.ts b/src/services/progress/xp-service.ts
index 4de910e..d696059 100644
--- a/src/services/progress/xp-service.ts
+++ b/src/services/progress/xp-service.ts
@@ -197,7 +197,7 @@ async function assignGroupId(weekStartStr: string): Promise<string> {
  * 确保每周每个用户只有一行记录。
  * 首次获得本周 XP 时自动分配到 20-30 人的排行榜分组。
  */
-async function addToWeeklyXp(userId: string, amount: number): Promise<void> {
+export async function addToWeeklyXp(userId: string, amount: number): Promise<void> {
   const { weekStart, weekEnd } = getCurrentWeekRange();
   const weekStartStr = weekStart.toISOString().slice(0, 10);