Matching the "space" character class For matching whitespaces in a regular expression, the most common and best-known shorthand expression...

When deleting a record in your Rails app, Carrierwave automatically takes care of removing all associated files. However, the file...

This card is a general reminder to avoid the short version of a command option in shared code. It's...

If a project ist configured to spawn CI runners for tests or deployment when pushing to the Repo, a habit...

To attach files to your records, you will need a new database column representing the filename of the file...

When your Rails application server raises error, Capybara will fail your test when it clears the session after the last...

When your application is open for public sign up and sends out transactional e-mails to a large number of...

You can use git worktree to manage multiple working trees attached to the same repository. But why should I use...

When you repeat a subpattern with a *, + or {...} operator, you may choose between greedy, lazy and possessive modes. Switching modes...

bundle outdated [--filter-major|--filter-minor|--filter-patch] Example output for bundle outdated --filter-major Other examples

By default, your terminal emulator (Gnome Terminal, Terminator, etc.) sets some kind of window title to reflect the shell type...

There are several tools for DNS debugging which offer you more or less information. Most of the time the more...

The Truemail gem (not to be confused with truemail.io) allows validating email addresses, e.g. when users enter them into a...

In long diffs, it can become impossible to spot small changes in larger blocks of moved code. This may be...

Headless Chrome is a way to run the Chrome browser without a visible window. Configuring Capybara Configure the Capybara driver...

Sometimes you want to find the inverse of an ActiveRecord scope. Depending on what you want to achieve, this is...

If you want to get the path of a file relative to another, you can use the expand_path method...

CSS variables are very different from preprocessor variables. While preprocessors use variables to compile a static piece of CSS, CSS...

When you use Sentry to monitor exceptions, an important feature is Sentry's error grouping mechanism. It will aggregate similar...

Rails middlewares are small code pieces that wrap requests to the application. The first middleware gets passed the request, invokes...

If you want to prevent that two processes run some code at the same time you can use the gem...

We use Sentry to be informed about different kinds of issues. One of the key features is that you are...

"Open-source software (OSS) is great. Anyone can use virtually any open-source code in their projects." Well, it depends...

If you have a :string or :text field, you should pair it with a model validation that restricts its length...