Capybara has no built-in switch for disabling cookies in browser tests; a small Rack middleware can strip request cookies so scenarios can verify sign-in failures without them.

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.

Forms can fail validation without visible feedback when the offending field has no input. A development-only error box keeps all form errors visible without leaving debug markup behind.

Quickly gauge which database tables are growing unnoticed by checking approximate row counts in PostgreSQL or MySQL.

includes can duplicate primary keys in ids when loading associated records, causing unexpected non-unique results; preload keeps the ids list stable.

html_safe strings lose $1 and other match variables inside gsub blocks. A SafeBuffer override can restore access to capture groups during replacements.

unscope removes selected ActiveRecord scope constraints such as where and order, while unscoped returns an entirely unconstrained relation.

Multiple column changes in a migration can trigger repeated SQL and slow large tables; change_table can bundle them into one ALTER TABLE statement.

Serve CSS at request time from Sass templates while keeping asset_path, imports, and injected theme colors available. Useful when styles need dynamic values without ERB preprocessing.

Capistrano 3 replaces the old DSL with Rake and SSHKit, changing task syntax, hooks, server settings, and file layout during migration from Capistrano 2.

Capybara/Selenium tests involve a test process, a server thread and a browser process, so blocking, stale time, and uncommitted transactions can cause seemingly impossible failures.

PDF generation via wkhtmltopdf can fail on Passenger when the wrong binary is used or routing errors trigger deadlocks. Pointing PDFKit to a working local executable avoids the command failure.

Large CarrierWave stores can overload a single directory with too many entries, slowing navigation and filesystem operations. Splitting record IDs into nested folders keeps directories manageable.

Large PostgreSQL databases can hide tables that consume most disk space. pg_total_relation_size and pg_size_pretty help identify the biggest relations quickly.

Geordi 1.3 adds Cucumber support with @solo handling, Capistrano 2/3 deployment fixes, and updated Firefox setup for selenium testing.

Flash-free copy-to-clipboard handling with clipboard.js, including success and error callbacks, text selection feedback, and support for text fields or data attributes.

Cucumber can use RSpec doubles instead of Mocha; loading the integration in env.rb keeps stubs and mocks available after other After hooks.

rake db:rollback can do nothing when the latest migrated version has no matching migration file, often after switching branches or deleting a migration.

External redirects are awkward to test with Cucumber and Capybara: Rack::Test ignores the host, while Selenium follows it. Controller specs or an observable redirect make the target URL verifiable.

has_many :through associations can lose or duplicate records when written to, especially with nested forms and loaded associations. Treat them as read-only or build the join records directly.

Inspecting callback chains in controller specs helps verify before- and after-action behavior, especially when tests need to confirm filter order or presence.

Rendering helper output with content_tag can get clumsy; Haml::Engine lets helper methods build HTML fragments more readably, with access to other helpers and locals.

Ruby arrays can be split into fixed-size groups or a chosen number of groups with ActiveSupport, padding or omitting leftovers as needed.

PG::ObjectInUse blocks dropping or resetting a PostgreSQL database when other sessions stay connected. Find the backend PID and terminate the process when needed.