fix: non-HTMLElement(s) fail during assertions (#30947)

Author: mschile

cli/CHANGELOG.md

@@ -6,6 +6,7 @@ _Released 1/28/2025 (PENDING)_
 **Bugfixes:**
 
 - Fixed an issue where Cypress would incorrectly navigate to `about:blank` when test isolation was disabled and the last test would fail and then retry. Fixes [#28527](https://github.com/cypress-io/cypress/issues/28527).
+- Fixed an issue where non-HTMLElement(s) may fail during assertions. Fixes [#30944](https://github.com/cypress-io/cypress/issues/30944)
 
 **Misc:**
 

packages/driver/cypress/e2e/commands/assertions.cy.js

@@ -939,6 +939,17 @@ describe('src/cy/commands/assertions', () => {
       expect(2n).to.equal(2n)
     })
 
+    it('handles non-HTMLElement(s) (e.g. Element)', () => {
+      const xml = '<?xml version="1.0" encoding="UTF-8"?><foo><bar>Bar</bar></foo>'
+      const parser = new DOMParser()
+      const doc = parser.parseFromString(xml, 'application/xml')
+      const foo = doc.getElementsByTagName('foo')[0]
+
+      expect(foo).not.to.be.undefined
+      expect(foo).to.be.instanceOf(Element)
+      expect(foo).not.to.be.instanceOf(HTMLElement)
+    })
+
     it('#consoleProps for regular objects', (done) => {
       cy.on('log:added', (attrs, log) => {
         if (attrs.name === 'assert') {

packages/driver/src/dom/visibility.ts

@@ -130,13 +130,11 @@ const elHasNoEffectiveWidthOrHeight = ($el: JQuery) => {
   // display:none elements, and generally any elements that are not directly rendered,
   // an empty list is returned.
   const el = $el[0]
-  let transform
 
-  if ($el[0].style.transform) {
-    const style = getComputedStyle(el)
+  const style = getComputedStyle(el)
+  let transform = style.getPropertyValue('transform')
 
-    transform = style.getPropertyValue('transform')
-  } else {
+  if (!transform.length) {
     transform = 'none'
   }