Pause Cucumber browser-driven tests between steps for debugging or demos, with single-step input and slower playback for @javascript Selenium runs.

Leaving a failing test at the end of unfinished work makes it easier to resume later and quickly see what still needs attention.

Stop the terminal from jumping back to the bottom when new output appears, so you can inspect logs or test failures without losing your place.

Tests and experiments around CSS features, possibilities, and browser bugs across more than 200 cases.

Cucumber step for checking whether a CSS selector is present or absent on a page with Capybara or Webrat.

Test suites that depend on remote APIs can become brittle and slow; an embedded Sinatra app provides a lightweight stub server for isolated integration tests.

Bootable media can be tested quickly in QEMU instead of setting up VirtualBox, using an ISO or a USB drive directly.

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.

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

Sidekiq retries can run out silently, leaving failed jobs only in the dead queue. Add explicit notification logic when permanent worker errors exhaust retries.

Detecting overflow in an element matters when layout must avoid hidden content and unwanted scroll bars; comparing scrollHeight and offsetHeight reveals whether content exceeds the visible area.

A simple visual test gauges how close a screen comes to true Retina quality by comparing fine line sharpness in two images.

Rake tasks can report exceptions to Airbrake without notifying in development or test environments, using the usual notification rules for tasks that depend on :environment.

Hidden-element checks in Capybara can fail in Selenium when visibility is inferred too loosely. A JavaScript-based step works across Selenium, jQuery, Prototype, and Rack::Test.

Stub a method on every instance of a class to control behavior in tests, using stub_any_instance, any_instance.stub, or allow_any_instance_of.

Create a user factory that accepts one full-name value and splits it into first and last name automatically, reducing repetitive test setup.

Rails app localization affects text, URLs, formats, images, caching, and time zones; estimating effort means checking each layer for language-sensitive behavior.

Testing a gem across Rails versions is easier with shared app code and specs via symlinks, keeping one test setup aligned with current best practice.

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

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

Quick RSpec-to-Jasmine 2 reference for matching expectations and mock assertions when switching test style; Jasmine 1.x uses different syntax.

JavaScript linting catches style and quality issues early, with a flat config, RSpec check, and gradual cleanup of existing offenses.

Webpacker integrates webpack with Rails to bundle JavaScript, stylesheets, images, and other assets, with Yarn managing dependencies and loaders handling non-JavaScript files.

fake_stripe runs a local Stripe-like server and fake Stripe.js for feature specs, letting purchase flows be tested without external HTTP requests or Stripe sandbox flakiness.