Warm up the OSM cache from batch fetches

app/services/osm.js

@@ -457,11 +457,11 @@ out center;
     // request using comma-separated IDs (max ~50 per request).
     //
     // Note: the multi-fetch endpoint returns ways/relations WITHOUT their child
-    // nodes, so normalized data may lack lat/lon and geometry. We intentionally
-    // do NOT write these results to the general OSM cache — only the returned
-    // Map is used by the caller (the contributions service manages its own
-    // name cache). This prevents incomplete data from breaking place detail
-    // navigation, which needs the full single-object endpoint.
+    // nodes, so normalized data may lack lat/lon and geometry.
+    // We only write complete results (those with lat/lon) to the general OSM
+    // cache. Nodes from the batch endpoint always include coordinates, so they
+    // are cached. Ways/relations without child node coordinates are not cached,
+    // preserving the full single-object endpoint for place detail navigation.
     const MAX_IDS_PER_REQUEST = 50;
 
     for (let i = 0; i < group.length; i += MAX_IDS_PER_REQUEST) {
@@ -488,6 +488,21 @@ out center;
           );
           if (normalized) {
             result.set(item.cacheKey, normalized);
+            // Warm the OSM cache for complete results (nodes always have
+            // lat/lon from the batch endpoint; ways/relations only when
+            // child nodes are included in the response).
+            if (
+              normalized.lat != null &&
+              normalized.lon != null &&
+              normalized.title
+            ) {
+              this._storeInMemoryAndLocalStorage(
+                item.cacheKey,
+                osmType,
+                item.osmId,
+                normalized
+              );
+            }
           }
         }
       } catch (e) {

tests/unit/services/osm-test.js

@@ -329,7 +329,7 @@ module('Unit | Service | osm', function (hooks) {
     );
   });
 
-  test('fetchOsmObjectsBatch does not write to the general OSM cache', async function (assert) {
+  test('fetchOsmObjectsBatch writes complete results to the general OSM cache', async function (assert) {
     let service = this.owner.lookup('service:osm');
 
     service.fetchWithRetry = async () => ({
@@ -343,13 +343,38 @@ module('Unit | Service | osm', function (hooks) {
 
     await service.fetchOsmObjectsBatch([{ osmType: 'node', osmId: '100' }]);
 
-    assert.false(
+    assert.true(
       service.cachedPlaces.has('node:100'),
-      'Batch fetch does not write to the in-memory OSM cache'
+      'Batch fetch writes complete results (with lat/lon) to the in-memory OSM cache'
+    );
+    assert.ok(
+      await service.localForage.get('osm-cache', 'node:100'),
+      'Batch fetch writes complete results to the persistent OSM cache'
+    );
+  });
+
+  test('fetchOsmObjectsBatch does NOT cache incomplete results without lat/lon', async function (assert) {
+    let service = this.owner.lookup('service:osm');
+
+    // Way without child nodes in the response -> no lat/lon in normalized result
+    service.fetchWithRetry = async () => ({
+      ok: true,
+      json: async () => ({
+        elements: [
+          { id: 200, type: 'way', nodes: [], tags: { name: 'Way 200' } },
+        ],
+      }),
+    });
+
+    await service.fetchOsmObjectsBatch([{ osmType: 'way', osmId: '200' }]);
+
+    assert.false(
+      service.cachedPlaces.has('way:200'),
+      'Batch fetch does NOT cache incomplete results (ways without child nodes)'
     );
     assert.notOk(
-      await service.localForage.get('osm-cache', 'node:100'),
-      'Batch fetch does not write to the persistent OSM cache'
+      await service.localForage.get('osm-cache', 'way:200'),
+      'Batch fetch does NOT write incomplete results to persistent cache'
     );
   });