Make VectorTileFeature#id a public property

README.md

@@ -93,6 +93,7 @@ An object that contains the data for a single feature.
 
 - **type** (`Number`) — type of the feature (also see `VectorTileFeature.types`)
 - **extent** (`Number`) — feature extent size
+- **id** (`Number`) — feature identifier, if present
 - **properties** (`Object`) — object literal with feature properties
 
 #### Methods

lib/vectortilefeature.js

@@ -20,7 +20,7 @@ function VectorTileFeature(pbf, end, extent, keys, values) {
 }
 
 function readFeature(tag, feature, pbf) {
-    if (tag == 1) feature._id = pbf.readVarint();
+    if (tag == 1) feature.id = pbf.readVarint();
     else if (tag == 2) readTag(pbf, feature);
     else if (tag == 3) feature.type = pbf.readVarint();
     else if (tag == 4) feature._geometry = pbf.pos;
@@ -185,8 +185,8 @@ VectorTileFeature.prototype.toGeoJSON = function(x, y, z) {
         properties: this.properties
     };
 
-    if ('_id' in this) {
-        result.id = this._id;
+    if ('id' in this) {
+        result.id = this.id;
     }
 
     return result;

test/parse.test.js

@@ -58,6 +58,8 @@ test('parsing vector tiles', function(t) {
             var park = tile.layers.poi_label.feature(1e9);
         }, 'throws on reading a feature out of bounds');
 
+        t.equal(park.id, 3000003150561);
+
         t.equal(park.properties.name, 'Mauerpark');
         t.equal(park.properties.type, 'Park');