Precise, low-level prompts and tight context improve AI code edits across files; structured keywords, reusable patterns, and early review reduce guesses and errors.

Local HTTPS development often needs a trusted certificate; openssl or mkcert can create self-signed X.509 certificates for testing without browser warnings.

Automatically saves failed Capybara test HTML and screenshots to tmp/capybara, helping diagnose flaky browser failures in Cucumber, RSpec, and Minitest.

Captures browser screenshots on demand or automatically when tests fail, making visual debugging of Capybara runs easier.

Reek detects Ruby code smells and antipatterns, helping assess merge request quality without blocking every warning. It fits CI as a non-blocking lint check.

Script to migrate test suites from RSpec 2 to RSpec 3, including syntax beyond should and expect.

Ruby 1.9 code coverage tool with configurable reporting and automatic merging across test suites; rcov remains for Ruby 1.8.

receive(:method_name) stubs the original method implementation, so callbacks or side effects do not run during expectations. and_call_original preserves the real behavior.

Custom Bundler groups can still be downloaded during Capistrano deploys, slowing production and staging releases. Exclude unnecessary groups with bundle_without to avoid installing unused gems.

Rails 5 upgrade can fail when the database schema lacks configured environment data, especially during parallel test database migration.

Packaging API bindings as a custom Ruby gem makes reuse and distribution easier, with tests recording HTTP interactions through VCR.

Checks a server hostname for the Heartbleed vulnerability in OpenSSL (CVE-2014-0160).

Migrating a Rails app from Sprockets-only asset handling to esbuild adds modern JavaScript bundling and can surface path, font, and Sass compatibility issues.

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.

Temporary request URLs make it easy to inspect HTTP callbacks and webhooks; incoming traffic is recorded and displayed for debugging.

Rails exception handling can either crash requests, hide actionable errors, or spam trackers; ExceptionApp, DebugExceptions, and the error reporter shape responses, logging, and notifications.

Capture CSP violation reports in a log file to spot blocked resources and browser-extension noise, with a dedicated Rails endpoint for incoming reports.

Cucumber CI rerun logic can pass green after syntax errors when no failing_features file is written; native --retry avoids this edge case.

CoffeeScript in checks array membership, not object properties; JavaScript in tests whether an object has a property. Use of for property lookup in CoffeeScript.

HTML email styling is fragile across clients and devices, making transactional messages hard to build and test. Open-source templates reduce the work needed for common transactional emails.

Large Rails projects benefit from keeping application tasks slim, separating the executable wrapper from the business code, and testing both rake tasks and scripts.

Email client styling support is fragmented, so feature checks help avoid unsupported CSS but cannot replace real-client rendering tests.

Eventually you’ll forget that you used to spend hours testing your code in a browser, and start complaining that your automated tests are taking minutes to run! You’ll have intense debates with co-workers about what to test and how to test it properly. You’ll start writing the test first to expose the bug or missing feature, then write the code required to pass the test.