refactor: expose portable source record protocols

src/data/tomtomTiles.js

@@ -26,12 +26,26 @@ const MERCATOR_LAT_LIMIT = 85.05112878;
  * @param {number} z - Zoom level; integer within [MIN_TILE_ZOOM, MAX_TILE_ZOOM].
  * @param {number} x - Tile column; integer within [0, 2^z - 1].
  * @param {number} y - Tile row; integer within [0, 2^z - 1].
+ * @param {{minZoom?: number, maxZoom?: number}} [bounds] Supported source zooms.
  * @returns {boolean} True when the coordinate is a fetchable tile.
  */
-export function isValidTileCoord(z, x, y) {
+export function isValidTileCoord(
+  z,
+  x,
+  y,
+  { minZoom = MIN_TILE_ZOOM, maxZoom = MAX_TILE_ZOOM } = {},
+) {
   if (!Number.isInteger(z) || !Number.isInteger(x) || !Number.isInteger(y))
     return false;
-  if (z < MIN_TILE_ZOOM || z > MAX_TILE_ZOOM) return false;
+  if (
+    !Number.isInteger(minZoom) ||
+    !Number.isInteger(maxZoom) ||
+    minZoom < 0 ||
+    maxZoom > 30 ||
+    minZoom > maxZoom
+  )
+    return false;
+  if (z < minZoom || z > maxZoom) return false;
   const n = 2 ** z;
   return x >= 0 && x < n && y >= 0 && y < n;
 }