Justin Tadlock

JavaScript Logic is a plugin that allows you to add JavaScript however you want. There’s no need to add a script on all of your blog’s pages when you only need it on a few.
By using WordPress conditional tags or through a meta box on the Write Post/Page screen, you control what files are added to your site and when.

JavaScript Logic

Allows you to load JavaScript in a much more controlled way using WordPress conditional tags.

WordPress.org

This plugin offloads JavaScript execution to a Web Worker, improving performance by freeing up the main thread. This should translate into improved <a href="https://web.dev/articles/inp" rel="nofollow ugc">Interaction to Next Paint</a> (INP) scores.
⚠ This functionality is experimental, and it is now <a href="https://github.com/WordPress/performance/issues/2284" rel="nofollow ugc">intended to be sunset</a>. ⚠
In order to opt in a script to be loaded in a worker, simply add <code>worker</code> script data to a registered script. For example, 
if you have a script registered with the handle of <code>foo</code>, opt-in to offload it to a web worker by doing:
<pre><code>wp_script_add_data( 'foo', 'worker', true );
</code></pre>
Unlike with the script loading strategies (async/defer), any inline before/after scripts associated with the worker-offloaded registered script will also be offloaded to the worker, whereas with the script strategies an inline after script would block the script from being delayed.
Otherwise, the plugin currently ships with built-in integrations to offload Google Analytics to a web worker for the following plugin:
<ul>
<li><a href="https://wordpress.org/plugins/seo-by-rank-math/" rel="ugc">Rank Math SEO</a></li>
<li><a href="https://wordpress.org/plugins/google-site-kit/" rel="ugc">Site Kit by Google</a></li>
<li><a href="https://wordpress.org/plugins/woocommerce/" rel="ugc">WooCommerce</a></li>
</ul>
Please monitor your analytics once activating to ensure all the expected events are being logged. At the same time, monitor your INP scores to check for improvement.
This plugin relies on the <a href="https://partytown.builder.io/" rel="nofollow ugc">Partytown 🎉</a> library by Builder.io, released under the MIT license. This library is in beta and there are quite a few <a href="https://github.com/BuilderIO/partytown/issues?q=is%3Aopen+is%3Aissue+label%3Abug" rel="nofollow ugc">open bugs</a>.
The <a href="https://partytown.builder.io/configuration" rel="nofollow ugc">Partytown configuration</a> can be modified via the <code>plwwo_configuration</code> filter. For example:
<pre><code><?php
add_filter( 'plwwo_configuration', function ( $config ) {
 $config['mainWindowAccessors'][] = 'wp'; // Make the wp global available in the worker (e.g. wp.i18n and wp.hooks).
 return $config;
} );
</code></pre>
However, not all of the configuration options can be serialized to JSON in this way, for example the <code>resolveUrl</code> configuration is a function. To specify this, you can add an inline script as follows.
<pre><code><?php
add_action(
 'wp_enqueue_scripts',
 function () {
 wp_add_inline_script(
 'web-worker-offloading',
 <<<JS
 window.partytown = {
 ...(window.partytown || {}),
 resolveUrl: (url, location, type) => {
 if (type === 'script') {
 const proxyUrl = new URL('https://my-reverse-proxy.example.com/');
 proxyUrl.searchParams.append('url', url.href);
 return proxyUrl;
 }
 return url;
 },
 };
 JS,
 'before'
 );
 }
);
</code></pre>
There are also many configuration options which are not documented, so refer to the <a href="https://github.com/BuilderIO/partytown/blob/b292a14047a0c12ca05ba97df1833935d42fdb66/src/lib/types.ts#L393-L548" rel="nofollow ugc">TypeScript definitions</a>.

Web Worker Offloading

Offloads select JavaScript execution to a Web Worker to reduce work on the main thread and improve the Interaction to Next Paint (INP) metric.

JavaScript Logic vs Web Worker Offloading