From bb2425e612b2ae4184207672947f40a1bb954883 Mon Sep 17 00:00:00 2001
From: Vincent Koc <vincentkoc@ieee.org>
Date: Sun, 26 Apr 2026 02:51:26 -0700
Subject: [PATCH] test(plugins): enforce compat removal window

---
 docs/plugins/compatibility.md       |  8 ++++----
 src/plugins/compat/registry.test.ts | 12 ++++++++++++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/docs/plugins/compatibility.md b/docs/plugins/compatibility.md
index 363f1777b17..7e6a641f54a 100644
--- a/docs/plugins/compatibility.md
+++ b/docs/plugins/compatibility.md
@@ -71,10 +71,10 @@ The migration sequence is:
 7. Remove only with explicit breaking-release approval.
 
 Deprecated records must include a warning start date, replacement, docs link,
-and target removal date no more than three months after deprecation. Do not add
-a deprecated compatibility path with an open-ended removal window unless
-maintainers explicitly decide it is permanent compatibility and mark it
-`active` instead.
+and final removal date no more than three months after the warning starts. Do
+not add a deprecated compatibility path with an open-ended removal window unless
+maintainers explicitly decide it is permanent compatibility and mark it `active`
+instead.
 
 ## Current compatibility areas
 
diff --git a/src/plugins/compat/registry.test.ts b/src/plugins/compat/registry.test.ts
index 88b8112f128..f15b8e439c5 100644
--- a/src/plugins/compat/registry.test.ts
+++ b/src/plugins/compat/registry.test.ts
@@ -9,6 +9,16 @@ import {
 
 const datePattern = /^\d{4}-\d{2}-\d{2}$/u;
 
+function parseDate(date: string): Date {
+  return new Date(`${date}T00:00:00Z`);
+}
+
+function addUtcMonths(date: Date, months: number): Date {
+  const next = new Date(date);
+  next.setUTCMonth(next.getUTCMonth() + months);
+  return next;
+}
+
 describe("plugin compatibility registry", () => {
   it("keeps compatibility codes unique and lookup-safe", () => {
     const records = listPluginCompatRecords();
@@ -25,6 +35,8 @@ describe("plugin compatibility registry", () => {
       expect(record.deprecated, record.code).toMatch(datePattern);
       expect(record.warningStarts, record.code).toMatch(datePattern);
       expect(record.removeAfter, record.code).toMatch(datePattern);
+      const maxRemoveAfter = addUtcMonths(parseDate(record.warningStarts), 3);
+      expect(parseDate(record.removeAfter) <= maxRemoveAfter, record.code).toBe(true);
       expect(record.replacement, record.code).toBeTruthy();
       expect(record.docsPath, record.code).toMatch(/^\//u);
     }