CircularInstance.addData was incorrect

addData takes a single object of type CircularChartData, not an array. Also the index is optional. See addData example in the documentation http://www.chartjs.org/docs/#doughnut-pie-chart-prototype-methods

chartjs/chart.d.ts

@@ -113,7 +113,7 @@ interface LinearInstance extends ChartInstance {
 interface CircularInstance extends ChartInstance {
     getSegmentsAtEvent: (event: Event) => {}[];
     update: () => void;
-    addData: (valuesArray: CircularChartData[], index: number) => void;
+    addData: (valuesArray: CircularChartData, index?: number) => void;
     removeData: (index: number) => void;
 }