Remove trailing slash with htaccess with existing rules - .htaccess

Question

I wish to remove a trailing slash when one is given using htaccess. What would be the best way to do it that will work with my existing rules as below:
# make sure www. is always there
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ https://www.%{HTTP_HOST}/$1 [R=301,L]
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
# if requested url does not exist pass it as path info to index.php
RewriteRule ^$ index.php?/ [QSA,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule (.*) index.php?/$1 [QSA,L]
A sample URL would be something like:
https://www.example.com/this-test/
I of course want the ending slash removed.
I've tried this:
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)/$ /$1 [R,L]
But that does not work with the existing rules that are there. It ends up redirecting to the index.php pages due to the other rules.

Answer 1

Have it this way:
Options -MultiViews
DirectoryIndex index.php
RewriteEngine On
# add www and turn on https in same rule
RewriteCond %{HTTP_HOST} !^www\. [NC,OR]
RewriteCond %{HTTPS} !on
RewriteCond %{HTTP_HOST} ^(?:www\.)?(.+)$ [NC]
RewriteRule ^ https://www.%1%{REQUEST_URI} [R=301,L,NE]
# Unless directory, remove trailing slash
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} ^(.+)/+$
RewriteRule ^ %1 [R=301,NE,L]
# if requested url does not exist pass it as path info to index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule .* index.php?/$0 [QSA,L]
Make sure to test it after completely clearing browser cache.