Rails 3 dbconsole misreads -p test and opens the development database unless the environment is passed first.

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

Selenium tests can fail with ActionView::Template::Error and a dump format error for a symbol, often caused by stale cached files in tmp/cache.

Need production or staging data for migration tests without a full database export; mysqldump can dump only selected tables when a complete dump is too large.

Verify that a value was created by a specific constructor in Jasmine with jasmine.any(Klass) instead of direct instance checks.

Custom Cucumber step for checking that a dropdown’s options are in order, with a Capybara matcher for natural sorting.

Testing resource_controller callbacks directly avoids triggering the action path and verifies hook behavior in controller specs.

Capybara can match elements outside body, including head nodes and hidden links, which helps test metadata and feed autodiscovery.

Exact form-field matching in Cucumber prevents false positives from partial values, while wildcards allow flexible contains-style checks.

Rails app boot and test startup become slow as gems grow; Zeus preloads the app so console, server, generate, and specs run in under a second.

Haml 6 renders most custom attributes verbatim, so falsy values no longer remove them. Boolean attributes keep special handling, and Haml::BOOLEAN_ATTRIBUTES can extend that list.

Capybara and Cucumber can assert whether a labeled form control is present or absent, with step definitions needing adjustment across older Capybara versions.

Capybara and Selenium can access only browser globals, so exported JavaScript modules fail in evaluate_script unless the component instance is attached to the element.

Capybara text checks can match a <textarea> instead of rendered page text; filtering to visible static content avoids false positives.

Cucumber step definitions for asserting whether visible link text is present or absent in Webrat or Capybara using selector-based matchers.

Ruby 1.8.7 test runs can fail with Gem::LOADED_SPECS_MUTEX NameError under older Bundler; Bundler 1.16.1 resolves it.

JavaScript has become essential for production applications, but maintainable code still depends on structured design, object-oriented principles, and test-driven development.

Check a download or page response by its MIME type in Cucumber, using Webrat or Capybara; the Selenium webdriver does not support this approach.

Paperclip attachment checks can give false positives because the attribute returns an attachment object. Use exists? to test whether a file is actually attached.

Console input tests are tricky because stubbing Kernel#gets often has no effect. Targeting the object or class that actually calls gets makes terminal input mocks work.

Create and verify bcrypt password hashes for Apache authentication, with safer handling than command-line password entry.

esbuild code splitting can reduce main-bundle size, but multiple entry points, chunk cascades, and import-order changes can break builds or runtime behavior.

Spreewald Cucumber steps can verify that e-mails were sent with arbitrary conditions, useful for testing mail dispatch logic.

A reusable Cucumber step triggers hover events on matched page elements, useful with Spreewald and BEM selector auto-mapping in feature tests.