Add PiechartType enum

packages/grafana-ui/src/components/index.ts

@@ -26,4 +26,4 @@ export { ValueMappingsEditor } from './ValueMappingsEditor/ValueMappingsEditor';
 export { Gauge } from './Gauge/Gauge';
 export { Switch } from './Switch/Switch';
 export { EmptySearchResult } from './EmptySearchResult/EmptySearchResult';
-export { Piechart, PiechartDataPoint } from './Piechart/Piechart';
+export { Piechart, PiechartDataPoint, PiechartType } from './Piechart/Piechart';

public/app/plugins/panel/piechart/types.ts

+import { PiechartType } from '@grafana/ui';
+
 export interface PiechartOptions {
-  pieType: string;
+  pieType: PiechartType;
   strokeWidth: number;
 
   valueOptions: PiechartValueOptions;
@@ -12,7 +14,7 @@ export interface PiechartValueOptions {
 }
 
 export const defaults: PiechartOptions = {
-  pieType: 'pie',
+  pieType: PiechartType.PIE,
   strokeWidth: 1,
   valueOptions: {
     unit: 'short',