jimbo2150

This plugin extends the WP_Scripts class, adding some additional methods and filters that overload the existing script output to add Require.js syntax. It loads scripts via Require.js and by default defers until the DOMContentLoaded event fires (unless a manually added require() is called within the head/body and does not wait for the DOM to be loaded. 
It is designed to work in conjunction with HTTP/2 but will function fine without it (though you may see slower load times).
This plugin is design to assist developers in updating and creating JavaScript that is asynchronous – that is, scripts that can load in a different order and do not assume that their dependencies are available immediately. Use of the Asynchronous Module Definition (AMD) allows a script to define it’s dependencies and have them loaded asynchronously prior to the entire script or the initialization portion executes.
It is common for larger projects to concatenate together scripts however, they can end up a jumbled mess and smaller required functions are often duplicated (and redundant) across multiple scripts. HTTP/2 corrects this by allowing multiple resource files to be requested and downloaded within a single TCP window. As projects get larger and more diverse it is becoming more economical to load the individual components (modules) that are needed rather than download and execute one massive concatenated script file (which can also cause the browser to freeze up).
NOTE: This plugin currently only replaces non-administrative (front-end) scripts with Require.js syntax.
Plugin website: https://techie-jim.net/wordpress-plugins/requirewp/

RequireWP

Uses Require.js to load scripts faster and speed up WordPress / increase site load speed & performance. Designed to work with HTTP/2.

Palasthotel

greatestview

In some critical cases you cannot wait for a JavaScript file to load. Then you can benefit from better performance, if you embed the JavaScript code directly into the <code><script></code> tag. This is where this plugin comes in: It provides a filter <code>embed_javascript_file_content_handles</code>, which takes JavaScript handles and echos their code content into the DOM instead of linking to a file.
Please beware that placing lots of embedded JavaScript code can be critical! First you lose caching benefits and second the document size can increase easily. A general rule of thumb is that you should only consider JavaScript files for inline placement, which are critical and which have a file size lower than ~500 Bytes.
<h4>Example</h4>
<pre><code>add_action( 'wp_enqueue_scripts', 'my_scripts' );
function my_scripts() {
 // Some critical script is enqueued
 wp_enqueue_script( 'js-detection', get_template_directory_uri() . '/js/js-detection.js' );
}

/**
 * Define JavaScript handles to be echoed inline in the html head section.
 */
add_filter( 'embed_javascript_file_content_handles', 'my_embed_javascript_file_content_handles' );
function my_embed_javascript_file_content_handles( $handles ) {
 $scripts = [ 'js-detection' ];

 return array_merge( $handles, $scripts );
}
</code></pre>

Embed JavaScript File Content

Boosts performance of critical short JavaScript files by allowing to embed their code instead of linking to files. Script positions and extra scripts  …

RequireWP vs Embed JavaScript File Content