Rejected non-fast-forward pushes happen after rewriting shared history; git push --force overwrites the remote branch and can make collaborators lose commits.

Change a Git commit message before it is pushed or merged. git commit --amend updates the latest commit; interactive rebase can rewrite earlier ones.

Older unpushed commits can be amended by folding a later fix commit into them with interactive rebase and fixup, preserving history without a new visible correction commit.

Untrusted YAML can instantiate arbitrary Ruby objects and set their fields, creating a serious deserialization risk. JSON.parse or YAML.safe_load are safer alternatives.

Controller specs can fail without reaching controller code when authentication is missing, no request is triggered, or views stay unrendered.

Use the Launchy gem:

Launchy.open('http://www.ruby-lang.org/')

Gallery of fonts you can use without much hassle in LaTeX. The license of the fonts vary, but are all free. Note that the fonts not necessarily are free to distribute, and some fonts are available for non-commercial use only.

Temporarily switch directories in Ruby without leaving the process in a different working folder by using Dir.chdir with a block.

The first thing you need to understand is that the purpose of refinements in Ruby 2.0 is to make monkey-patching safer. Specifically, the goal is to make it possible to extend core classes, but to limit the effect of those extensions to a particular area of code. Since the purpose of this feature is make monkey-patching safer, let’s take a look at a dangerous case of monkey-patching and see how this new feature would improve the situation.

NULL values break database calculations because arithmetic propagates NULL; IFNULL substitutes a fallback value so expressions continue to evaluate.

jQuery's selector engine, live()-like event handlers, pixel-perfect layout measuring.

Store associated values as a single array-like field, editable in forms and restored safely after validation errors, while syncing to the underlying relation.

RubyMine on Ubuntu can be installed as a snap with automatic updates or set up manually from the legacy archive. Configuration stays in ~/.config/JetBrains/RubyMine<version> with classic confinement.

Because Nokogiri needs to be compiled and dynamically linked against both libxml2 and libxslt, it has gained a reputation for being complicated to install. Let’s wrassle this little myth to the ground, shall we?

When rendering a partial with the :collection option, you are automatically provided with a counter variable inside the partial template.

Trace stray puts and p output in Ruby by inserting a temporary hook that prints a backtrace for a chosen message, then remove it after cleanup.

Reduce attention-grabbing interruptions by stopping Thunderbird 3 from checking mail automatically at startup, on intervals, or via server IDLE notifications.

Complex joined queries can return ActiveRecord objects with the wrong primary key when select pulls columns from multiple tables. Restricting the projection to users. preserves the correct id.

Multiple check boxes can bind to an array-backed virtual attribute, making tag selection and validation-safe form round trips work with one value per option.

Navigate to the previous page in Cucumber feature tests when browser history is unavailable, using the HTTP referrer in Capybara or Webrat.

Selenium has been the siren song that continually calls out to us. Unfortunately, in practice we’ve been unable to get Selenium to run reliably for real applications, on both developers machines and on the continuous integration server. This failure with Selenium has caused us to search for alternative solutions

Change the message of the latest unpushed Git commit with git commit --amend, or rewrite older unpushed commit messages with interactive rebase.

Rails gems that must support several framework releases need separate test apps per version. Shared code and specs reduce duplication while keeping version-specific coverage.

Checks whether a form dropdown has a preselected value in HTML using Cucumber step definitions for Capybara or Webrat.