[9.2] [Vega] add object normalization (#238503) (#240017)

# Backport

This will backport the following commits from `main` to `9.2`:
- [[Vega] add object normalization
(#238503)](#238503)

<!--- Backport version: 9.6.6 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

<!--BACKPORT [{"author":{"name":"Marco
Vettorello","email":"marco.vettorello@elastic.co"},"sourceCommit":{"committedDate":"2025-10-22T07:44:33Z","message":"[Vega]
add object normalization (#238503)\n\n## Summary\n\nAdd object
normalization to Vega warning/error
messages","sha":"4d51ac82208dde420739bcc9ffb0c762e6192d20","branchLabelMapping":{"^v9.3.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["bug","Team:Visualizations","release_note:skip","ci:build-os-packages","backport:all-open","v9.3.0"],"title":"[Vega]
add object
normalization","number":238503,"url":"https://github.com/elastic/kibana/pull/238503","mergeCommit":{"message":"[Vega]
add object normalization (#238503)\n\n## Summary\n\nAdd object
normalization to Vega warning/error
messages","sha":"4d51ac82208dde420739bcc9ffb0c762e6192d20"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v9.3.0","branchLabelMappingKey":"^v9.3.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/238503","number":238503,"mergeCommit":{"message":"[Vega]
add object normalization (#238503)\n\n## Summary\n\nAdd object
normalization to Vega warning/error
messages","sha":"4d51ac82208dde420739bcc9ffb0c762e6192d20"}}]}]
BACKPORT-->

Co-authored-by: Marco Vettorello <marco.vettorello@elastic.co>

Author: kibanamachine

src/platform/plugins/private/vis_types/vega/public/data_model/utils.ts

@@ -10,34 +10,33 @@
 import compactStringify from 'json-stringify-pretty-compact';
 import type { CoreTheme } from '@kbn/core/public';
 import { getEuiThemeVars } from '@kbn/ui-theme';
+import { normalizeObject } from '../vega_view/utils';
+
+function normalizeAndStringify(value: unknown) {
+  if (typeof value === 'string') {
+    return value;
+  }
+  return compactStringify(normalizeObject(value), { maxLength: 70 });
+}
 
 export class Utils {
   /**
    * If the 2nd array parameter in args exists, append it to the warning/error string value
    */
-  static formatWarningToStr(...args: any[]) {
-    let value = args[0];
+  static formatWarningToStr(...args: any[]): string {
+    const value = normalizeAndStringify(args[0]);
     if (args.length >= 2) {
       try {
-        if (typeof args[1] === 'string') {
-          value += `\n${args[1]}`;
-        } else {
-          value += '\n' + compactStringify(args[1], { maxLength: 70 });
-        }
+        return `${value}\n${normalizeAndStringify(args[1])}`;
       } catch (err) {
-        // ignore
+        return Utils.formatErrorToStr(err);
       }
     }
     return value;
   }
 
-  static formatErrorToStr(...args: any[]) {
-    let error: Error | string = args[0];
-    if (!error) {
-      error = 'ERR';
-    } else if (error instanceof Error) {
-      error = error.message;
-    }
+  static formatErrorToStr(...args: unknown[]) {
+    const error: string = args[0] instanceof Error ? args[0].message : 'Error';
     return Utils.formatWarningToStr(error, ...Array.from(args).slice(1));
   }
 }

src/platform/plugins/private/vis_types/vega/public/data_model/vega_parser.ts

@@ -272,8 +272,11 @@ The URL is an identifier only. Kibana and your browser will never access this UR
       }
     }
     this.vlspec = this.spec;
-    const vegaLogger = logger(Warn); // note: eslint has a false positive here
-    vegaLogger.warn = this._onWarning.bind(this);
+    const vegaLogger = logger(Warn);
+    vegaLogger.warn = (...args) => {
+      this._onWarning(...args);
+      return vegaLogger;
+    };
     this.spec = compile(this.vlspec as TopLevelSpec, { logger: vegaLogger }).spec;
 
     // When using Vega-Lite (VL) with the type=map and user did not provid their own projection settings,
@@ -776,8 +779,8 @@ The URL is an identifier only. Kibana and your browser will never access this UR
    */
   _onWarning(...args: any[]) {
     if (!this.hideWarnings) {
-      this.warnings.push(Utils.formatWarningToStr(args));
-      return Utils.formatWarningToStr(args);
+      this.warnings.push(Utils.formatWarningToStr(...args));
+      return Utils.formatWarningToStr(...args);
     }
   }
 }

src/platform/plugins/private/vis_types/vega/public/vega_view/utils.test.ts

@@ -48,13 +48,13 @@ describe('normalizeObject', () => {
   test('should throw if a function is given as the object property', async () => {
     expect(() => {
       normalizeObject({ toJSON: () => alert('gotcha') });
-    }).toThrow('a function cannot be used as a property name');
+    }).toThrow('Object normalization error');
   });
 
   test('should throw if a function is given on a nested object', async () => {
     expect(() => {
       normalizeObject({ test: { toJSON: () => alert('gotcha') } });
-    }).toThrow('a function cannot be used as a property name');
+    }).toThrow('Object normalization error');
   });
 
   test('should return null for null', async () => {

src/platform/plugins/private/vis_types/vega/public/vega_view/utils.ts

@@ -48,7 +48,9 @@ export function checkObjectForFunctionProperty(object: unknown): boolean {
   */
 export function normalizeObject(object: unknown) {
   if (checkObjectForFunctionProperty(object)) {
-    throw new Error('a function cannot be used as a property name');
+    throw new Error('Object normalization error', {
+      cause: 'A function cannot be used as a property name',
+    });
   }
   const normalizedObject = object ? JSON.parse(JSON.stringify(object)) : null;
   ensureNoUnsafeProperties(normalizedObject);

src/platform/plugins/private/vis_types/vega/public/vega_view/vega_base_view.js

@@ -241,23 +241,29 @@ export class VegaBaseView {
 
     const vegaLogger = logger(Warn);
 
-    vegaLogger.warn = this.onWarn.bind(this);
-    vegaLogger.error = this.onError.bind(this);
+    vegaLogger.warn = (...args) => {
+      this.onWarn(...args);
+      return vegaLogger;
+    };
+    vegaLogger.error = (...args) => {
+      this.onError(...args);
+      return vegaLogger;
+    };
 
     config.logger = vegaLogger;
 
     return config;
   }
 
-  onError() {
-    const error = Utils.formatErrorToStr(...arguments);
+  onError(...args) {
+    const error = Utils.formatErrorToStr(...args);
     this._addMessage('err', error);
     this._parser.searchAPI.inspectorAdapters?.vega.setError(error);
   }
 
-  onWarn() {
+  onWarn(...args) {
     if (this._renderMode !== 'view' && (!this._parser || !this._parser.hideWarnings)) {
-      this._addMessage('warn', Utils.formatWarningToStr(...arguments));
+      this._addMessage('warn', Utils.formatWarningToStr(...args));
     }
   }