DashboardDS: Clone series to not mutate original frames (#104518)

* DashboardDS: Clone series to not mutate original frames

* rename test

public/app/plugins/datasource/dashboard/datasource.test.ts

@@ -102,6 +102,26 @@ describe('DashboardDatasource', () => {
 
     expect(first).not.toHaveBeenCalled();
   });
+
+  it('Should not mutate field state in dataframe', () => {
+    const { observable } = setup({ refId: 'A', panelId: 1, withTransforms: true });
+
+    let rsp: DataQueryResponse | undefined;
+
+    const test = observable.subscribe({ next: (data) => (rsp = data) });
+
+    // modifying series in dashboard DS should not affect the original dataframe
+    rsp!.data[0].fields[0].state = {
+      calcs: { sum: 3 },
+    };
+
+    test.unsubscribe();
+
+    observable.subscribe({ next: (data) => (rsp = data) });
+
+    // on further emissions the result should be the unmodified original dataframe
+    expect(rsp!.data[0].fields[0].state).toEqual({});
+  });
 });
 
 function setup(query: DashboardQuery, requestId?: string) {

public/app/plugins/datasource/dashboard/datasource.ts

@@ -11,6 +11,7 @@ import {
   PanelData,
   DataFrame,
   LoadingState,
+  Field,
 } from '@grafana/data';
 import { SceneDataProvider, SceneDataTransformer, SceneObject } from '@grafana/scenes';
 import {
@@ -104,7 +105,19 @@ export class DashboardDatasource extends DataSourceApi<DashboardQuery> {
         },
       }));
     } else {
-      return [...data.series, ...annotations];
+      const series = data.series.map((s) => {
+        return {
+          ...s,
+          fields: s.fields.map((field: Field) => ({
+            ...field,
+            state: {
+              ...field.state,
+            },
+          })),
+        };
+      });
+
+      return [...series, ...annotations];
     }
   }