From 4f7fcc8f101d76c8b2fc749a33dfd20b603a5acf Mon Sep 17 00:00:00 2001
From: Demetrio Girardi <dgirardi@prebid.org>
Date: Wed, 27 Sep 2023 07:01:25 -0700
Subject: [PATCH] Core: do not log errors about invalid XML when serializing
 XHR objects (#10483)

---
 src/ajax.js                      | 24 +++++++++++++++---------
 test/spec/unit/core/ajax_spec.js | 22 +++++++++++++++++-----
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/src/ajax.js b/src/ajax.js
index 0601cc0e22b..6f2f45e935e 100644
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -89,6 +89,17 @@ export function fetcherFactory(timeout = 3000, {request, done} = {}) {
 
 function toXHR({status, statusText = '', headers, url}, responseText) {
   let xml = 0;
+  function getXML(onError) {
+    if (xml === 0) {
+      try {
+        xml = new DOMParser().parseFromString(responseText, headers?.get(CTYPE)?.split(';')?.[0])
+      } catch (e) {
+        xml = null;
+        onError && onError(e)
+      }
+    }
+    return xml;
+  }
   return {
     readyState: XMLHttpRequest.DONE,
     status,
@@ -98,17 +109,12 @@ function toXHR({status, statusText = '', headers, url}, responseText) {
     responseType: '',
     responseURL: url,
     get responseXML() {
-      if (xml === 0) {
-        try {
-          xml = new DOMParser().parseFromString(responseText, headers?.get(CTYPE)?.split(';')?.[0])
-        } catch (e) {
-          xml = null;
-          logError(e);
-        }
-      }
-      return xml;
+      return getXML(logError);
     },
     getResponseHeader: (header) => headers?.has(header) ? headers.get(header) : null,
+    toJSON() {
+      return Object.assign({responseXML: getXML()}, this)
+    }
   }
 }
 
diff --git a/test/spec/unit/core/ajax_spec.js b/test/spec/unit/core/ajax_spec.js
index df0ce02c15c..a3a0459b980 100644
--- a/test/spec/unit/core/ajax_spec.js
+++ b/test/spec/unit/core/ajax_spec.js
@@ -1,7 +1,8 @@
-import {dep, attachCallbacks, fetcherFactory, toFetchRequest} from '../../../../src/ajax.js';
+import {attachCallbacks, dep, fetcherFactory, toFetchRequest} from '../../../../src/ajax.js';
 import {config} from 'src/config.js';
 import {server} from '../../../mocks/xhr.js';
-import {sandbox} from 'sinon';
+import * as utils from 'src/utils.js';
+import {logError} from 'src/utils.js';
 
 const EXAMPLE_URL = 'https://www.example.com';
 
@@ -312,13 +313,24 @@ describe('attachCallbacks', () => {
     const cbType = success ? 'success' : 'error';
 
     describe(`for ${t}`, () => {
-      let response, body;
+      let sandbox, response, body;
       beforeEach(() => {
+        sandbox = sinon.sandbox.create();
+        sandbox.spy(utils, 'logError');
         ({response, body} = makeResponse());
       });
 
+      afterEach(() => {
+        sandbox.restore();
+      })
+
       function checkXHR(xhr) {
-        sinon.assert.match(xhr, {
+        utils.logError.resetHistory();
+        const serialized = JSON.parse(JSON.stringify(xhr))
+        // serialization of `responseXML` should not generate console messages
+        sinon.assert.notCalled(utils.logError);
+
+        sinon.assert.match(serialized, {
           readyState: XMLHttpRequest.DONE,
           status: response.status,
           statusText: response.statusText,
@@ -330,7 +342,7 @@ describe('attachCallbacks', () => {
         if (xml) {
           expect(xhr.responseXML.querySelectorAll('*').length > 0).to.be.true;
         } else {
-          expect(xhr.responseXML).to.not.exist;
+          expect(serialized.responseXML).to.not.exist;
         }
         Array.from(response.headers.entries()).forEach(([name, value]) => {
           expect(xhr.getResponseHeader(name)).to.eql(value);