TextPanel: Fixes problems where text panel would show old content (#28643)

public/app/plugins/panel/text/textPanelMigrationHandler.test.ts

@@ -8,12 +8,30 @@ describe('textPanelMigrationHandler', () => {
       const panel: any = {
         content: '<span>Hello World<span>',
         mode: 'html',
+        options: {},
       };
 
       const result = textPanelMigrationHandler(panel);
 
       expect(result.content).toEqual('<span>Hello World<span>');
       expect(result.mode).toEqual('html');
+      expect(panel.content).toBeUndefined();
+      expect(panel.mode).toBeUndefined();
+    });
+  });
+
+  describe('when invoked and previous version 7.1 or later', () => {
+    it('then not migrate options', () => {
+      const panel: any = {
+        content: '<span>Hello World<span>',
+        mode: 'html',
+        options: { content: 'New content' },
+        pluginVersion: '7.1.0',
+      };
+
+      const result = textPanelMigrationHandler(panel);
+
+      expect(result.content).toEqual('New content');
     });
   });
 

public/app/plugins/panel/text/textPanelMigrationHandler.ts

@@ -2,19 +2,27 @@ import { PanelModel } from '@grafana/data';
 import { TextMode, TextOptions } from './types';
 
 export const textPanelMigrationHandler = (panel: PanelModel<TextOptions>): Partial<TextOptions> => {
+  const previousVersion = parseFloat(panel.pluginVersion || '6.1');
+  let options = panel.options;
+
   // Migrates old Angular based text panel props to new props
   if (panel.hasOwnProperty('content') && panel.hasOwnProperty('mode')) {
-    const oldTextPanel: { content: string; mode: string } = (panel as unknown) as any;
+    const oldTextPanel: any = panel as any;
     const content = oldTextPanel.content;
-    const mode = (oldTextPanel.mode as unknown) as TextMode;
+    const mode = oldTextPanel.mode as TextMode;
+
+    delete oldTextPanel.content;
+    delete oldTextPanel.mode;
 
-    return { content, mode };
+    if (previousVersion < 7.1) {
+      options = { content, mode };
+    }
   }
 
   // The 'text' mode has been removed so we need to update any panels still using it to markdown
-  if (panel.options.mode !== 'html' && panel.options.mode !== 'markdown') {
-    return { content: panel.options.content, mode: 'markdown' };
+  if (options.mode !== 'html' && options.mode !== 'markdown') {
+    options = { ...options, mode: 'markdown' };
   }
 
-  return panel.options;
+  return options;
 };