Clone layerObject in Style#addLayer to prevent mutation of user data

mapbox · Aug 1, 2017 · ae0712b · ae0712b
1 parent 1fe5c95
commit ae0712b
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diff --git a/src/style/style.js b/src/style/style.js
@@ -497,6 +497,7 @@ class Style extends Evented {
 
         if (typeof layerObject.source === 'object') {
             this.addSource(id, layerObject.source);
+            layerObject = util.clone(layerObject);
             layerObject = (util.extend(layerObject, {source: id}): any);
         }
 

diff --git a/test/unit/style/style.test.js b/test/unit/style/style.test.js
@@ -723,6 +723,23 @@ test('Style#addLayer', (t) => {
         });
     });
 
+    t.test('#4040 does not mutate source property when provided inline', (t) => {
+        const style = new Style(createStyleJSON());
+        style.on('style.load', () => {
+            const source = {
+                "type": "geojson",
+                "data": {
+                    "type": "Point",
+                    "coordinates": [ 0, 0]
+                }
+            };
+            const layer = {id: 'inline-source-layer', type: 'circle', source: source };
+            style.addLayer(layer);
+            t.deepEqual(layer.source, source);
+            t.end();
+        });
+    });
+
     t.test('reloads source', (t) => {
         const style = new Style(util.extend(createStyleJSON(), {
             "sources": {