Nested form elements can vanish or submit the wrong data because browsers handle invalid form markup inconsistently, especially during Ajax updates.

Capybara.javascript_test? checks whether the current driver supports JavaScript, helping feature tests switch behavior for Selenium, capybara-webkit, Poltergeist, and custom drivers.

BigDecimal#floor returns different types in Ruby 1.8 and 1.9 because it depends on Float#floor; a backport restores the Ruby 1.9 behavior on Ruby 1.8.

bin/webpack-dev-server can fail with Yarn's "Command "webpack-dev-server" not found" error when dependencies are missing; yarn install --check-files restores the command.

Malformed commit timestamps can make git clone fail with badTimezone when strict object validation is enabled. Disabling fetch.fsckobjects works around the error.

Judging legacy code by today’s needs hides the uncertainty faced during initial development, where many architecture and technology choices were made with incomplete information.

Unexpected executable bits can appear on normal project files after copying from Windows or a Samba share. geordi remove-executable-flags clears them recursively with chmod -x.

Records loaded with SQL fragments in :select or :joins become read-only in ActiveRecord to avoid saving rows with noncolumn attributes. :readonly => false overrides the safeguard.

Exchange can discard the plaintext part of multipart/alternative email, leaving only HTML in normal mail accounts and complicating debugging.

Update every entry in a Ruby Hash with a concise merge! trick when each key needs a new computed value.

Limit Unicorn to one worker in development to keep debugging output manageable and prevent concurrent requests like ActionCable from flooding the console.

Connecting Ruby on Ubuntu to Microsoft SQL Server can require nonstandard drivers and native libraries, especially for older SQL Server versions on Linux.

better_errors adds enhanced development error pages with a live REPL, and /__better_errors lets you inspect exceptions from AJAX requests.

Nested form deletions can inflate aggregated totals when child records marked for removal are still counted. marked_for_destruction? filters them out before saving.

any_instance stubbing and expectations now work in RSpec 2.6, enabling should_receive and stub on instances created inside code.

Find the most frequent string in an array without failing on empty input; the approach uses grouping and returns the first value from the largest group.

Whenever can misread 24-hour times without a leading zero, turning 3:00 into 3pm instead of 3am. chronic_options can switch parsing to a 24-hour clock.

Handy ActiveSupport helpers add callbacks, message signing and encryption, ordered options, array wrapping, deep hash merging, whitespace squishing, and zone-aware current time.

Integrating cross-cutting concerns in Ruby can reduce duplication and keep logging, security, and other shared behavior separate from core business logic.