pre()

nebula.pre()

nebula.pre = async function(){
    //Format non-shortcode pre tags to be styled properly
    jQuery('pre.nebula-code').each(async function(){
        await nebula.yield();

        if ( !jQuery(this).parent('.nebula-code-con').length ){
            let lang = jQuery(this).attr('data-lang') || '';
            if ( lang === '' ){
                let langMatches = jQuery(this).attr('class').match(/lang(?:uage)?-(\S*)/i);
                lang = ( langMatches )? langMatches[0] : ''; //Use a class that starts with "lang-" or "language-" Ex: "lang-JavaScript"
            }
            if ( lang === '' ){
                lang = jQuery(this).attr('class').replace('nebula-code', '').replaceAll(/(\s*)((wp|m.|p.|nebula)-\S+)(\s*)/gi, '').trim(); //Remove expected classes and use remaining class as language
            }

            lang = escape(lang); //Escape for reuse into the DOM

            jQuery(this).addClass(lang.toLowerCase()).wrap('<div class="nebula-code-con clearfix ' + lang.toLowerCase() + '"></div>');
            jQuery(this).closest('.nebula-code-con').prepend('<span class="nebula-code codetitle ' + lang.toLowerCase() + '">' + lang + '</span>');
        }
    });

    //Manage copying snippets to clipboard
    if ( 'clipboard' in navigator ){
        jQuery('.nebula-code-con').each(function(){
            jQuery(this).append('<a href="#" class="nebula-selectcopy-code">Copy to Clipboard</a>');
            jQuery(this).find('p:empty').remove(); //Sometimes WordPress adds extra/empty <p> tags. These mess with spacing, so we remove them.
        });

        nebula.dom.document.on('click', '.nebula-selectcopy-code', function(){
            let $oThis = jQuery(this);
            if ( $oThis.hasClass('error') ){ //If we already errored, stop trying
                return false;
            }

            let text = jQuery(this).closest('.nebula-code-con').find('pre').text();

            navigator.clipboard.writeText(text).then(function(){
                $oThis.text('Copied!').removeClass('error').addClass('success');
                setTimeout(function(){
                    $oThis.text('Copy to clipboard').removeClass('success');
                }, 1500);
            }).catch(function(error){ //This can happen if the user denies clipboard permissions
                gtag('event', 'Exception', { //Report the error to Google Analytics to log it
                    message: '(JS) Clipboard API error: ' + error,
                    fatal: false
                });

                $oThis.text('Unable to copy.').addClass('error');
            });

            return false;
        });
    }
};

For non-module import functions:

nebula.pre = function(){
    //Write your own code here, leave it blank, or return false.
}

For dynamically imported module function overrides:

jQuery(window).on('load', function(){
    nebula.pre = function(){
        //Write your own code here, leave it blank, or return false.
    }
});

Custom Nebula DOM events do also exist, so you could also try the following if the Window Load listener does not work:

jQuery(document).on('nebula_module_loaded', function(module){
    //Note that the module variable is also available to know which module specifically was imported
    if ( typeof nebula.pre === 'function' ){
        nebula.pre = function(){
            //Write your own code here, leave it blank, or return false.
        }
	}
});