cleanup and guess all columns

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

@@ -0,0 +1,60 @@
+// Library
+import React from 'react';
+
+import { DataPanel, getProcessedTableData } from './DataPanel';
+
+describe('DataPanel', () => {
+  let dataPanel: DataPanel;
+
+  beforeEach(() => {
+    dataPanel = new DataPanel({
+      queries: [],
+      panelId: 1,
+      widthPixels: 100,
+      refreshCounter: 1,
+      datasource: 'xxx',
+      children: r => {
+        return <div>hello</div>;
+      },
+      onError: (message, error) => {},
+    });
+  });
+
+  it('starts with unloaded state', () => {
+    expect(dataPanel.state.isFirstLoad).toBe(true);
+  });
+
+  it('converts timeseries to table skipping nulls', () => {
+    const input1 = {
+      target: 'Field Name',
+      datapoints: [[100, 1], [200, 2]],
+    };
+    const input2 = {
+      // without target
+      target: '',
+      datapoints: [[100, 1], [200, 2]],
+    };
+    const data = getProcessedTableData([null, input1, input2, null, null]);
+    expect(data.length).toBe(2);
+    expect(data[0].columns[0].text).toBe(input1.target);
+    expect(data[0].rows).toBe(input1.datapoints);
+
+    // Default name
+    expect(data[1].columns[0].text).toEqual('Value');
+
+    // Every colun should have a name and a type
+    for (const table of data) {
+      for (const column of table.columns) {
+        expect(column.text).toBeDefined();
+        expect(column.type).toBeDefined();
+      }
+    }
+  });
+
+  it('supports null values from query OK', () => {
+    expect(getProcessedTableData([null, null, null, null])).toEqual([]);
+    expect(getProcessedTableData(undefined)).toEqual([]);
+    expect(getProcessedTableData((null as unknown) as any[])).toEqual([]);
+    expect(getProcessedTableData([])).toEqual([]);
+  });
+});

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

@@ -15,6 +15,7 @@ import {
   TimeRange,
   ScopedVars,
   toTableData,
+  guessColumnTypes,
 } from '@grafana/ui';
 
 interface RenderProps {
@@ -46,6 +47,25 @@ export interface State {
   data?: TableData[];
 }
 
+/**
+ * All panels will be passed tables that have our best guess at colum type set
+ *
+ * This is also used by PanelChrome for snapshot support
+ */
+export function getProcessedTableData(results?: any[]): TableData[] {
+  if (!results) {
+    return [];
+  }
+
+  const tables: TableData[] = [];
+  for (const r of results) {
+    if (r) {
+      tables.push(guessColumnTypes(toTableData(r)));
+    }
+  }
+  return tables;
+}
+
 export class DataPanel extends Component<Props, State> {
   static defaultProps = {
     isVisible: true,
@@ -147,7 +167,7 @@ export class DataPanel extends Component<Props, State> {
       this.setState({
         loading: LoadingState.Done,
         response: resp,
-        data: toTableData(resp.data),
+        data: getProcessedTableData(resp.data),
         isFirstLoad: false,
       });
     } catch (err) {

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

@@ -19,11 +19,13 @@ import config from 'app/core/config';
 // Types
 import { DashboardModel, PanelModel } from '../state';
 import { PanelPlugin } from 'app/types';
-import { DataQueryResponse, TimeRange, LoadingState, TableData, DataQueryError, toTableData } from '@grafana/ui';
+import { DataQueryResponse, TimeRange, LoadingState, TableData, DataQueryError } from '@grafana/ui';
 import { ScopedVars } from '@grafana/ui';
 
 import templateSrv from 'app/features/templating/template_srv';
 
+import { getProcessedTableData } from './DataPanel';
+
 const DEFAULT_PLUGIN_ERROR = 'Error in plugin';
 
 export interface Props {
@@ -139,7 +141,7 @@ export class PanelChrome extends PureComponent<Props, State> {
   }
 
   get getDataForPanel() {
-    return this.hasPanelSnapshot ? toTableData(this.props.panel.snapshotData) : null;
+    return this.hasPanelSnapshot ? getProcessedTableData(this.props.panel.snapshotData) : null;
   }
 
   renderPanelPlugin(loading: LoadingState, data: TableData[], width: number, height: number): JSX.Element {