[Website] PHP Request errors don't show a error message

[bgrgicak]

When a PHP request throws a request error (e.g. PHP Fatal) the Website only prints the error to the browser console and the user sees a white screen (see screenshot).

We could help the user understand what happened if Playground showed an error message or opened the Logs modal instead of displaying a white screen.

PHP.wasm errors (internal to Playground) already do that by showing the Report error modal that contains logs.

Steps to recreate

• Open this Blueprint https://playground.wordpress.net/#%7B%22landingPage%22:%22/wp-admin/plugins.php%22,%22preferredVersions%22:%7B%22php%22:%227.4%22,%22wp%22:%225.9%22%7D,%22steps%22:%5B%7B%22step%22:%22login%22%7D,%7B%22step%22:%22installPlugin%22,%22pluginData%22:%7B%22resource%22:%22wordpress.org/plugins%22,%22slug%22:%22wordfence%22%7D,%22options%22:%7B%22activate%22:false%7D%7D%5D%7D
• Activate Wordfence Security
• See white screen
• See logs in the console

Screenshots

[adamziel]

Good point, it would be useful to send the same output as server-side PHP would. Let's figure out if that's ever stderr or is it always stdout and make sure it's sent with the response. Or are we already doing that, but there's nothing in stdout because WP_DEBUG is false ?

[bgrgicak]

I did some quick testing and both hosted WP and Playground behave the same.
What I'm suggesting would be an improvement that Playground can offer because it controls the full stack.

Testing details

I used a hosted WP site and Playground, both had the same WP_DEBUG options.

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );

255 error

In the issue description, PHP returns a 255 error which is internal to PHP.
Both Playground and hosted WP return an empty screen in this case.

Note The Playground Website has a black background by default and this is why the hosted WP shows a white screen and Playground a black screen.

Blueprint example

Hosted WP

Throw error

Here is an example of throwing a fatal error on the init hook, where both hosted WP and Playground behave the same.

Blueprint example

Hosted WP

[bgrgicak]

But now when I think about it, a 255 error is internal to PHP and that means it's internal to Playground.
We should show the Error report modal for all 255 errors even if they are request errors.