Panels: Fixes so panels are refreshed when scrolling past them fast (#30784)

public/app/features/dashboard/dashgrid/PanelChrome.test.tsx

+import React, { FC } from 'react';
+import { ReplaySubject } from 'rxjs';
+import { act, render, screen } from '@testing-library/react';
+import { getDefaultTimeRange, LoadingState, PanelData, PanelPlugin, PanelProps } from '@grafana/data';
+
+import { PanelChrome, Props } from './PanelChrome';
+import { DashboardModel, PanelModel } from '../state';
+import { updateLocation } from '../../../core/actions';
+import { PanelQueryRunner } from '../../query/state/PanelQueryRunner';
+import { setTimeSrv, TimeSrv } from '../services/TimeSrv';
+
+jest.mock('app/core/profiler', () => ({
+  profiler: {
+    renderingCompleted: jest.fn(),
+  },
+}));
+
+function setupTestContext(options: Partial<Props>) {
+  const subject: ReplaySubject<PanelData> = new ReplaySubject<PanelData>();
+  const panelQueryRunner = ({
+    getData: () => subject,
+    run: () => {
+      subject.next({ state: LoadingState.Done, series: [], timeRange: getDefaultTimeRange() });
+    },
+  } as unknown) as PanelQueryRunner;
+  const timeSrv = ({
+    timeRange: jest.fn(),
+  } as unknown) as TimeSrv;
+  setTimeSrv(timeSrv);
+  const defaults: Props = {
+    panel: ({
+      hasTitle: jest.fn(),
+      replaceVariables: jest.fn(),
+      events: { subscribe: jest.fn() },
+      getQueryRunner: () => panelQueryRunner,
+      getOptions: jest.fn(),
+    } as unknown) as PanelModel,
+    dashboard: ({
+      panelInitialized: jest.fn(),
+      getTimezone: () => 'browser',
+    } as unknown) as DashboardModel,
+    plugin: ({
+      meta: { skipDataQuery: false },
+      panel: TestPanelComponent,
+    } as unknown) as PanelPlugin,
+    isViewing: true,
+    isEditing: false,
+    isInView: false,
+    width: 100,
+    height: 100,
+    updateLocation: (jest.fn() as unknown) as typeof updateLocation,
+  };
+
+  const props = { ...defaults, ...options };
+  const { rerender } = render(<PanelChrome {...props} />);
+
+  return { rerender, props, subject };
+}
+
+describe('PanelChrome', () => {
+  describe('when the user scrolls by a panel so fast that it starts loading data but scrolls out of view', () => {
+    it('then it should load the panel successfully when scrolled into view again', () => {
+      const { rerender, props, subject } = setupTestContext({});
+
+      expect(screen.queryByText(/plugin panel to render/i)).not.toBeInTheDocument();
+
+      act(() => {
+        subject.next({ state: LoadingState.Loading, series: [], timeRange: getDefaultTimeRange() });
+        subject.next({ state: LoadingState.Done, series: [], timeRange: getDefaultTimeRange() });
+      });
+
+      const newProps = { ...props, isInView: true };
+      rerender(<PanelChrome {...newProps} />);
+
+      expect(screen.getByText(/plugin panel to render/i)).toBeInTheDocument();
+    });
+  });
+});
+
+const TestPanelComponent: FC<PanelProps> = () => <div>Plugin Panel to Render</div>;

public/app/features/dashboard/dashgrid/PanelChrome.tsx

@@ -140,6 +140,7 @@ export class PanelChrome extends Component<Props, State> {
     if (!this.props.isInView) {
     if (!this.props.isInView) {
       // Ignore events when not visible.
       // Ignore events when not visible.
       // The call will be repeated when the panel comes into view
       // The call will be repeated when the panel comes into view
+      this.setState({ refreshWhenInView: true });
       return;
       return;
     }
     }