From 8e1471d7af9544afefb9a5e031dba2000d694cbc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8E=8B=E5=BE=B7=E5=AE=87?= <kvtodev@outlook.com>
Date: Fri, 2 Oct 2026 19:23:36 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B5=8B=E8=AF=95(=E8=AE=A1=E8=B4=B9):=20?=
 =?UTF-8?q?=E5=9B=BA=E5=8C=96=E4=BC=9A=E5=91=98=E7=9B=AE=E5=BD=95=E4=BB=B7?=
 =?UTF-8?q?=E6=A0=BC=E4=B8=8E=E6=B3=A5=E7=82=B9=E9=9A=8F=20rank=20?=
 =?UTF-8?q?=E9=80=92=E5=A2=9E=E7=9A=84=E4=B8=8D=E5=8F=98=E9=87=8F?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

在 catalog 文档写明升级补差依赖的单调性不变量，并新增回归测试断言 rank 越高月价、年价、每期泥点严格递增

Co-authored-by: Junie <junie@jetbrains.com>
---
 .../module-runtime/src/membership/catalog.rs  | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/server-rs/crates/module-runtime/src/membership/catalog.rs b/server-rs/crates/module-runtime/src/membership/catalog.rs
index 1fee74750..e7d2860e3 100644
--- a/server-rs/crates/module-runtime/src/membership/catalog.rs
+++ b/server-rs/crates/module-runtime/src/membership/catalog.rs
@@ -8,6 +8,10 @@
 //! 价格是**后端唯一真相**，前端展示价只用于渲染，下单时后端按同一份目录重算。
 //!
 //! 本期模型权限只落字段、只用于展示，不做服务端拦截；并发上限只做判定，同样不拦截。
+//!
+//! 目录不变量：按 `rank` 升序，月价、年价、每期泥点必须**严格递增**（`Normal` 为 0）。
+//! 升级补差按 `rank` 判定、按价差 / 点差计价，若高 `rank` 的行反而更便宜或更少点，
+//! `saturating_sub` 会把补差静默算成 0；后台改价时不得破坏该不变量。
 
 use serde::{Deserialize, Serialize};
 
@@ -298,6 +302,35 @@ mod tests {
         assert!(is_unlimited_concurrency(max.concurrent_job_limit));
     }
 
+    #[test]
+    fn enabled_plans_increase_in_price_and_points_with_rank() {
+        // 中文注释：升级补差依赖「rank 越高、价格与每期泥点越大」这一不变量；
+        // 后台改价破坏它时，升级会静默算成 0，因此把种子目录的不变量固化成回归断言。
+        let mut rows = runtime_profile_membership_plan_catalog();
+        rows.sort_by_key(|row| row.rank);
+        for pair in rows.windows(2) {
+            let (lower, higher) = (&pair[0], &pair[1]);
+            assert!(
+                higher.month_price_cents > lower.month_price_cents,
+                "{} 的月价必须高于 {}",
+                higher.title,
+                lower.title
+            );
+            assert!(
+                higher.year_price_cents > lower.year_price_cents,
+                "{} 的年价必须高于 {}",
+                higher.title,
+                lower.title
+            );
+            assert!(
+                higher.period_points > lower.period_points,
+                "{} 的每期泥点必须高于 {}",
+                higher.title,
+                lower.title
+            );
+        }
+    }
+
     #[test]
     fn year_price_is_stored_independently_of_the_month_price() {
         // 中文注释：年价是独立可配置字段，这里断言的是种子数值本身，而不是月价 ×10 的推导关系。