Selects one commit from another branch without merging the whole branch. cherry-pick copies the change with a new hash, which can lead to duplicate history later.

Nokogiri can repair invalid HTML during parsing, which may break markup and SEO expectations. Using Nokogiri::XML with HTML save options preserves the original structure.

Enum values can become FactoryBot traits automatically, reducing manual trait definitions and making new roles or states available in tests with less setup.

Browser video playback needs format fallbacks, subtitles, and careful state handling; poster, controls, and the HTMLVideoElement API help build reliable players.

JavaScript’s object model hinges on prototypes, property descriptors, and this binding; understanding constructor functions, inheritance, and Object.getPrototypeOf() prevents common OOP pitfalls.

Combining properties from two JavaScript objects depends on the runtime: spread syntax, Object.assign(), or up.util.merge() can create a new object with later values winning.

jQuery-free dropdown components for advanced selects are needed when Select2 is too dependent on jQuery or missing features.

Background jobs in Rails can stay adapter-agnostic by using ActiveJob, making Sidekiq or Resque easy to swap without changing worker code.

Load large choice lists on demand with AJAX in Select2 to avoid huge HTML and support paged, infinite-scrolling results.

Markdown fields can become XSS sinks when user input is rendered unsafely, allowing javascript: links, image event handlers, and filter bypasses.

Older Ruby versions need pinned pry and debugger gems; incompatible releases trigger native extension build failures and frozen-string errors.

Unresponsive network calls can stall a Ruby system, and many gems default to no timeout. Safer timeout settings avoid hangs, with Ruby’s Timeout module best avoided.

Move existing Redis data to another server by temporarily turning the target into a replica, then detaching it after synchronization.

Selecting XML namespace elements with CSS in Nokogiri requires | instead of : for namespaced names like soapenv|Envelope.

Cucumber can report cucumber.yml as invalid even when it parses correctly; an invalid rerun file like tmp/rerun.txt may trigger the error.

RSpec tests are easier to maintain with clearer structure and disciplined style, but recommendations still need judgment; the Self-Contained Test is a complementary approach.

Mock expectations in RSpec can linger across examples; resetting a proxy removes the configured doubles and returns the object to its original state.

Conditional cron jobs in whenever can target only one Rails environment or Capistrano stage, avoiding unwanted tasks on other deployments.

Ruby method dispatch follows a fixed lookup chain across singleton classes, prepended modules, class methods, included modules, and superclasses.

Rake tasks can be verified in RSpec by expecting Rake::Task to receive invoke, useful for testing task-triggered side effects without putting logic in tasks.

git commit --fixup creates a follow-up commit that git rebase --autosquash can fold into an earlier change, keeping feature-branch history tidy.