From 023b116ad3d79ed6efe57e106beadc26d9d385f6 Mon Sep 17 00:00:00 2001
From: SandObserver <260779319+SandObserver@users.noreply.github.com>
Date: Mon, 19 Oct 2026 17:41:58 -0400
Subject: [PATCH] Prune each stored refresh by its own keep time

---
 api/src/latest.js       | 11 ++++++-----
 api/test/latest.test.js | 11 +++++++++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/api/src/latest.js b/api/src/latest.js
index 6de6ce2c..5302cf04 100644
--- a/api/src/latest.js
+++ b/api/src/latest.js
@@ -4,11 +4,11 @@
 
 /** @typedef {{ ok: true, value: any } | { ok: false, error: unknown }} Outcome */
 
-/** @type {Map<string, { started: number, at: number, outcome: Outcome | null, pending: Promise<Outcome> | null, group: string | null }>} */
+/** @type {Map<string, { started: number, at: number, keepMs: number, outcome: Outcome | null, pending: Promise<Outcome> | null, group: string | null }>} */
 const _entries = new Map();
 
-function prune(now, keepMs) {
-  for (const [key, e] of _entries) if (!e.pending && now - e.at >= keepMs) _entries.delete(key);
+function prune(now) {
+  for (const [key, e] of _entries) if (!e.pending && now - e.at >= e.keepMs) _entries.delete(key);
 }
 
 /* Drops the oldest settled entries of a group until at most max remain. A
@@ -40,13 +40,14 @@ function within(ms, pending) {
     @returns {Promise<Outcome | null>} */
 async function latest(key, refresh, { holdMs, keepMs, group, maxPerGroup }) {
   const now = Date.now();
-  prune(now, keepMs);
+  prune(now);
   let e = _entries.get(key);
   const created = !e;
   if (!e) {
-    e = { started: 0, at: 0, outcome: null, pending: null, group: group ?? null };
+    e = { started: 0, at: 0, keepMs, outcome: null, pending: null, group: group ?? null };
     _entries.set(key, e);
   }
+  e.keepMs = keepMs;
   const entry = e;
   if (!entry.pending) {
     entry.started = now;
diff --git a/api/test/latest.test.js b/api/test/latest.test.js
index 9cb5798d..6047cccd 100644
--- a/api/test/latest.test.js
+++ b/api/test/latest.test.js
@@ -61,6 +61,17 @@ test('a result older than keepMs is not used', async t => {
   assert.equal(await latest('k', () => new Promise(() => {}), { holdMs: 0, keepMs: OPTS.keepMs }), null);
 });
 
+test('a short keepMs on one key does not drop another key kept longer', async t => {
+  t.mock.timers.enable({ apis: ['Date'], now: 1_000_000 });
+  await latest('long', async () => 'kept', { holdMs: 30, keepMs: 15 * 60_000 });
+  t.mock.timers.tick(5 * 60_000);
+  await latest('short', async () => 'other', { holdMs: 30, keepMs: 2 * 60_000 });
+  assert.deepEqual(await latest('long', () => new Promise(() => {}), { holdMs: 0, keepMs: 15 * 60_000 }), {
+    ok: true,
+    value: 'kept',
+  });
+});
+
 test('different keys do not share a result', async () => {
   await latest('a', async () => 'a', OPTS);
   assert.deepEqual(await latest('b', async () => 'b', OPTS), { ok: true, value: 'b' });