fix(terrain): refresh cache recency when resolving warm batches

src/services/terrain-warm-batch-lru.test.mjs

@@ -0,0 +1,24 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { createTerrainHeights } from './terrainHeights.js';
+test('warm batch consumers retain their terrain cells ahead of unused cells', async () => {
+  let calls = 0;
+  const terrain = createTerrainHeights({
+    maxCacheEntries: 2,
+    source: {
+      async getHeights(points) {
+        calls++;
+        return points.map((p) => ({ ellipsoid: 100 + p.lon }));
+      },
+    },
+  });
+  const p = (lon) => ({ lat: 0, lon });
+  await terrain.resolveEllipsoidalGround([p(1)]);
+  await terrain.resolveEllipsoidalGround([p(2)]);
+  await terrain.resolveEllipsoidalGround([p(1)]);
+  assert.equal(calls, 2);
+  await terrain.resolveEllipsoidalGround([p(3)]);
+  assert.equal(terrain.cachedEllipsoidalGround(0, 1), 101);
+  assert.equal(terrain.cachedEllipsoidalGround(0, 2), null);
+  assert.equal(calls, 3);
+});

src/services/terrainHeights.js

@@ -273,7 +273,7 @@ export function createTerrainHeights({
     const seenKeys = new Set();
     const now = Date.now();
     for (const item of work) {
-      const entry = cache.get(item.key);
+      const entry = cacheTouch(item.key);
       const fallbackCooling =
         entry?.source === 'geoid-fallback' &&
         Number.isFinite(entry.retryAt) &&