kingkool68

<?php
// Put this in wp-config.php and replace https://example.com/ with the URL of the production site.
define( 'RH_USE_REMOTE_MEDIA_URL', 'https://example.com/' );

// Put the rest of this in functions.php or a custom plugin or somewhere else.
if ( defined( 'RH_USE_REMOTE_MEDIA_URL' ) && ! empty( RH_USE_REMOTE_MEDIA_URL ) ) {
	add_filter( 'wp_get_attachment_image_src', 'filter_wp_get_attachment_image_src' );
	add_filter( 'wp_calculate_image_srcset', 'filter_wp_calculate_image_srcset' );
	add_filter( 'wp_get_attachment_url', 'filter_wp_get_attachment_url' );
}

kdzwinel

/*
This script attempts to identify all CSS classes mentioned in HTML but not defined in the stylesheets.

In order to use it, just run it in the DevTools console (or add it to DevTools Snippets and run it from there).

Note that this script requires browser to support `fetch` and some ES6 features (fat arrow, Promises, Array.from, Set). You can transpile it to ES5 here: https://babeljs.io/repl/ .

Known limitations:
- it won't be able to take into account some external stylesheets (if CORS isn't set up) 
- it will produce false negatives for classes that are mentioned in the comments.

webaware

<?php
/*
Plugin Name: Force SSL URL Scheme
Plugin URI: https://gist.github.com/webaware/4688802
Description: Force the protocol scheme to be HTTPS when is_ssl() doesn't work
Version: 1.0.0
Author: WebAware
Author URI: http://webaware.com.au/

@ref: http://wordpress.org/support/topic/ssl-insecure-needs-35-compatibility