toDataFrame: detect field properties using in rather than hasOwnProperty (#23673)

packages/grafana-data/src/dataframe/processDataFrame.test.ts

@@ -10,6 +10,7 @@ import {
 import { DataFrameDTO, FieldType, TableData, TimeSeries } from '../types/index';
 import { dateTime } from '../datetime/moment_wrapper';
 import { MutableDataFrame } from './MutableDataFrame';
+import { ArrayDataFrame } from './ArrayDataFrame';
 
 describe('toDataFrame', () => {
   it('converts timeseries to series', () => {
@@ -73,6 +74,19 @@ describe('toDataFrame', () => {
     expect(again).toBe(input);
   });
 
+  it('Make sure ArrayDataFrame is used as a DataFrame without modification', () => {
+    const orig = [
+      { a: 1, b: 2 },
+      { a: 3, b: 4 },
+    ];
+    const array = new ArrayDataFrame(orig);
+    const frame = toDataFrame(array);
+    expect(frame).toEqual(array);
+    expect(frame instanceof ArrayDataFrame).toEqual(true);
+    expect(frame.length).toEqual(orig.length);
+    expect(frame.fields.map(f => f.name)).toEqual(['a', 'b']);
+  });
+
   it('throws when table rows is not array', () => {
     expect(() =>
       toDataFrame({

packages/grafana-data/src/dataframe/processDataFrame.ts

@@ -261,9 +261,9 @@ export const isTableData = (data: any): data is DataFrame => data && data.hasOwn
 export const isDataFrame = (data: any): data is DataFrame => data && data.hasOwnProperty('fields');
 
 export const toDataFrame = (data: any): DataFrame => {
-  if (data.hasOwnProperty('fields')) {
+  if ('fields' in data) {
     // DataFrameDTO does not have length
-    if (data.hasOwnProperty('length')) {
+    if ('length' in data) {
       return data as DataFrame;
     }