mvt: Add result.byteLength (#862)

visgl · Jul 17, 2020 · 073c877 · 073c877
1 parent eb691ed
commit 073c877
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Showing 2 changed files with 15 additions and 6 deletions.
diff --git a/modules/mvt/src/lib/parse-mvt.js b/modules/mvt/src/lib/parse-mvt.js
@@ -9,15 +9,15 @@ import {transformCoordinates, transformToLocalCoordinates} from './transform-to-
   * @param {arrayBuffer} _ A MVT arrayBuffer
   * @return {?Object} A GeoJSON geometry object
   */
-export default function parseMVT(input, options) {
+export default function parseMVT(arrayBuffer, options) {
   options = options || {};
   options.mvt = options.mvt || {};
 
-  if (input.byteLength === 0) {
+  if (arrayBuffer.byteLength === 0) {
     return [];
   }
 
-  const tile = new VectorTile(new Protobuf(input));
+  const tile = new VectorTile(new Protobuf(arrayBuffer));
   const loaderOptions = options.mvt;
   const features = [];
 
@@ -41,7 +41,14 @@ export default function parseMVT(input, options) {
     }
   });
 
-  return options.mvt._format === 'binary' ? geojsonToBinary(features) : features;
+  if (options.mvt._format === 'binary') {
+    const data = geojsonToBinary(features);
+    // TODO decide where to store this
+    // @ts-ignore
+    data.byteLength = arrayBuffer.byteLength;
+    return data;
+  }
+  return features;
 }
 
 function getDecodedFeature(feature, options = {}) {

diff --git a/modules/mvt/test/mvt-loader.spec.js b/modules/mvt/test/mvt-loader.spec.js
@@ -193,8 +193,10 @@ test('Polygon MVT to local coordinates binary', async t => {
   const response = await fetchFile(MVT_POLYGONS_DATA_URL);
   const mvtArrayBuffer = await response.arrayBuffer();
 
-  const geometryJSON = await parse(mvtArrayBuffer, MVTLoader, {mvt: {_format: 'binary'}});
-  t.deepEqual(geometryJSON, geojsonToBinary(decodedPolygonsGeometry));
+  const geometryBinary = await parse(mvtArrayBuffer, MVTLoader, {mvt: {_format: 'binary'}});
+  t.ok(geometryBinary.byteLength > 0);
+  delete geometryBinary.byteLength;
+  t.deepEqual(geometryBinary, geojsonToBinary(decodedPolygonsGeometry));
 
   t.end();
 });