Some pseudo-elements need to be addressed with vendor prefixes. E.g. ::selection is not supported by Firefox, you need to...
There are various ways to run external commands from within Ruby, but the most powerful ones are Open3.capture3 and Open3.popen3...
Website that offers lots of different kinds of HTTPS configurations, bad or good or complicated. They also offer a dashboard...
Adding a gem means you take over the liability towards the external code. Checklist Based on "To gem, or not...
We generally use multiple application servers (at least two) and you have to search on all of them if you...
First find the reference for the entry you want through looking at the stash: $ git stash list stash@{0}: WIP...
Collection of useful tools in the Chrome JavaScript console. Make the whole page editable This is not special to Chrome...
Sometimes huge refactorings or refactoring of core concepts of your application are necessary for being able to meet new requirements...
In general, you should not put a block element inside an inline element. So don't do this: text
This card tries to summarize by example the different uses of heredoc. In Ruby << vs. <<- vs. <<~ In Rails strip_heredoc...
xargs is a powerful bash tool that can take input from $STDIN and pass it to a given command. I.e...
There is no CSS selector for matching elements that contains a given string ¹. Luckily, Capybara offers the :text option to...
Instantiating ActiveRecord objects comes expensive. To speed up things, you can choose a more direct way to talk to your...
When working with custom transactions and use ActiveRecord::Rollback you may encounter unexpected behaviour if you try to roll back...
If you want to find the commits that touched a specific text in a file, use git log -S 'text...
Rails 5 / 6 / 7 Method Uses Default Accessor Saves to Database Runs Validations Runs Callbacks Updates updated_at/updated_on Respects Readonly...
Ruby's __FILE__ keyword returns the path to the current file. On popular for this are Ruby binaries: #!/usr/bin/env ruby...
When your controller action raises an unhandled exception, Rails will look at the exception's class and choose an appropriate...
PostgreSQL, unlike MySQL, treats strings as case sensitive in all circumstances. This includes comparison with = and LIKE collision detection in...
Is your application doing something expensive every few seconds? Maybe an animated slider that rotates images? Maybe you are updating...
By convention, common protocols use a defined port, like 80 for HTTP or 443 for HTTPS. You can use nmap...
When building a web application, one is tempted to claim it "done" too early. Make sure you check this list...
Chrome's developer tools automagically choose vertical or horizontal panel layout, based on their width. You can disable that magic...
PostgreSQL uses the C library's locale facilities for sorting strings: First, all the letters are compared, ignoring spaces and...