fix: Plugin "Check it!" button fails silently with nonce error #893

[kmfoysal06]

What?

Closes #893

The changes in this PR are to add a custom error notice in the UI instead of showing the error in the console when an error occurs in the catch block.

Why?

The issue mentioned above shows how, after some time, when the nonce gets expired, the check plugin button does not work and shows an invalid nonce message in the console. So, the solution is either to tell the user about the nonce expiration on the client side visually or reload the page automatically. As reloading the page won't be a consistent solution, I decided to show an admin error notice informing the user that the nonce has expired.

How?

My suggested solution is to show the error message from the server side directly as an admin error notice so the user can understand why the plugin check is failing.

Testing Instructions

1. Open 'Plugin Check' from Dashboard > Tools.
2. Open Browser DevTools and paste PLUGIN_CHECK.nonce = 'gg' and press Enter to make the nonce invalid.
3. Select any plugin and click the "Check It!" button to check the plugin.
4. The admin error notice will be visible with the error message from the server side.

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Before	After

Unlinked contributors: tamimhasan19702, rtpHarry.

Co-authored-by: kmfoysal06 kmfoysal06@git.wordpress.org
Co-authored-by: iyut aralle@git.wordpress.org

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[sajjadfaraj-dev]

I tested this PR locally against the current branch on Fedora.

Validation passed for me:

• npm run lint-js
• composer lint

The fix also looks nicely scoped to the reported failure.

One accessibility question: since #plugin-check__client-error becomes visible asynchronously after the request fails, would it be worth giving the notice alert/live-region semantics (for example role="alert"), so the new error is announced to screen-reader users without requiring focus to move to it?

Otherwise the visible error handling is a clear improvement over the current silent failure.

[kmfoysal06]

Hello @sajjadfaraj-dev
Thank you for your time reviewing this PR. I agree with you and I will let you know when I update the code to add the mentioned accessibility improvement.

[kmfoysal06]

Hello @sajjadfaraj-dev I just updated the alert. can you please review it again.