refactor: separate map feature queries and source records

src/sources/overpassRoads.js

@@ -0,0 +1,27 @@
+/** Decode OSM ways into portable road coordinates, classes and travel direction. */
+export function normalizeOverpassRoads(payload) {
+  const roads = [];
+  for (const element of payload?.elements || []) {
+    if (
+      element.type !== 'way' ||
+      !element.geometry ||
+      element.geometry.length < 2
+    )
+      continue;
+    const oneway = element.tags?.oneway;
+    roads.push({
+      coordinates: element.geometry.map((point) => [point.lon, point.lat]),
+      type: element.tags?.highway || 'unclassified',
+      oneway:
+        oneway === 'yes' ||
+        oneway === '1' ||
+        oneway === 'true' ||
+        element.tags?.junction === 'roundabout'
+          ? 1
+          : oneway === '-1'
+            ? -1
+            : 0,
+    });
+  }
+  return roads;
+}