I have a problem where I can't access the button inside the iFrame located inside the shadow element.
Here is the HTML code:
<mati-frame>
#shadow-root (open)
<iframe>
<button>
Start
</button>
</iframe>
</mati-frame>
Not sure what you tried. I found the test was flaky depending on how the iframe was set up.
Mostly it failed to find the iframe's contentDocument, but turning off chromeWebSecurity seems to give consistent results.
cypress.json
{
"chromeWebSecurity": false,
"includeShadowDom": true
}
Test
cy.get('mati-frame')
.find('iframe')
.its('0.contentDocument.body')
.find('button') // passes