Can syntax validation be enabled? It would be very helpful for users when editing PHP, JS, or CSS to know whether or not it has syntax errors.
Once that is active, on the theme and plugin editor screens, we should prevent saving the file if there are syntax errors. Likewise, for custom CSS in the customizer we should mark the setting as invalid to prevent it from being published.
Can syntax validation be enabled? It would be very helpful for users when editing PHP, JS, or CSS to know whether or not it has syntax errors.
Once that is active, on the theme and plugin editor screens, we should prevent saving the file if there are syntax errors. Likewise, for custom CSS in the customizer we should mark the setting as invalid to prevent it from being published.
See also https://core.trac.wordpress.org/ticket/39218