fix(imagery): mark CMR results truncated when the record cap drops valid granules

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/layers/recentImagery/catalog.js

@@ -27,7 +27,8 @@ const CMR_SEARCH_AFTER = 'CMR-Search-After';
 /**
  * Read one product's granules across CMR pages, sending back each response's
  * `CMR-Search-After` cursor until a short page, a missing cursor or the
- * record cap ends the walk. `truncated` is measured against CMR's `hits`.
+ * record cap ends the walk. `truncated` means CMR's `hits` exceed the rows
+ * read, or the cap dropped valid granules from the last page read.
  * @param {{ product: string, url: string, fetchImpl: typeof fetch, signal?: AbortSignal, maxRecords?: number }} request
  * @returns {Promise<{ granules: Array<object>, truncated: boolean }>}
  */
@@ -41,6 +42,7 @@ export async function fetchCmrPages({
   const granules = [];
   let hits = 0;
   let readCount = 0;
+  let capped = 0;
   let cursor = null;
   for (;;) {
     const init = { signal };
@@ -52,9 +54,12 @@ export async function fetchCmrPages({
     const rawCount = Array.isArray(json?.items) ? json.items.length : 0;
     const page = parseCmrUmm(json, product);
     readCount += rawCount;
-    granules.push(
+    const admitted = page.granules.slice(
-      ...page.granules.slice(0, Math.max(0, maxRecords - granules.length)),
+      0,
+      Math.max(0, maxRecords - granules.length),
     );
+    granules.push(...admitted);
+    capped += page.granules.length - admitted.length;
     hits = Math.max(hits, page.hits);
     cursor = response.headers?.get?.(CMR_SEARCH_AFTER) ?? null;
     if (
@@ -65,7 +70,7 @@ export async function fetchCmrPages({
     )
       break;
   }
-  return { granules, truncated: hits > readCount };
+  return { granules, truncated: hits > readCount || capped > 0 };
 }
 
 function finiteOrNull(value) {

src/layers/recentImagery/cmr-raw-page-budget.test.mjs

@@ -54,3 +54,45 @@ test('a non-page-multiple limit never returns more admitted records than its bud
   assert.equal(result.granules.length, 250);
   assert.equal(result.truncated, true);
 });
+test('valid records dropped by the cap mark the result truncated even when every hit was read', async () => {
+  let calls = 0;
+  const result = await fetchCmrPages({
+    product: 'S30',
+    url: 'fixture',
+    maxRecords: 250,
+    fetchImpl: async () => {
+      calls++;
+      return Response.json(
+        {
+          hits: 400,
+          items: Array.from({ length: 200 }, (_, i) => item(`${calls}:${i}`)),
+        },
+        { headers: { 'CMR-Search-After': `cursor-${calls}` } },
+      );
+    },
+  });
+  assert.equal(calls, 2);
+  assert.equal(result.granules.length, 250);
+  assert.equal(result.truncated, true);
+});
+test('malformed rows discarded under the cap leave a fully examined result untruncated', async () => {
+  let calls = 0;
+  const result = await fetchCmrPages({
+    product: 'S30',
+    url: 'fixture',
+    maxRecords: 250,
+    fetchImpl: async () => {
+      calls++;
+      const items = Array.from({ length: 200 }, (_, i) =>
+        calls === 2 && i >= 50 ? {} : item(`${calls}:${i}`),
+      );
+      return Response.json(
+        { hits: 400, items },
+        { headers: { 'CMR-Search-After': `cursor-${calls}` } },
+      );
+    },
+  });
+  assert.equal(calls, 2);
+  assert.equal(result.granules.length, 250);
+  assert.equal(result.truncated, false);
+});