[core] reload geojson source on url change

test/style/source.test.cpp

@@ -381,3 +381,37 @@ TEST(Source, RasterTileAttribution) {
 
     test.run();
 }
+
+TEST(Source, GeoJSonSourceUrlUpdate) {
+    SourceTest test;
+    
+    test.fileSource.sourceResponse = [&] (const Resource& resource) {
+        EXPECT_EQ("url", resource.url);
+        Response response;
+        response.data = std::make_unique<std::string>("{\"geometry\": {\"type\": \"Point\", \"coordinates\": [1.1, 1.1]}, \"type\": \"Feature\", \"properties\": {}}");
+        return response;
+    };
+
+    test.observer.sourceDescriptionChanged = [&] (Source&) {
+        //Should be called (test will hang if it doesn't)
+		test.end();
+    };
+
+    test.observer.tileError = [&] (Source&, const OverscaledTileID&, std::exception_ptr) {
+        FAIL() << "Should never be called";
+    };
+
+    GeoJSONSource source("source");
+    source.baseImpl->setObserver(&test.observer);
+    
+	//Load initial, so the source state will be loaded=true
+	source.baseImpl->loadDescription(test.fileSource);
+	
+	//Schedule an update
+	test.loop.invoke([&] () {
+		//Update the url
+		source.setURL(std::string("http://source-url.ext"));	
+	});	
+
+    test.run();
+}