Run multiple example or scenario line numbers from one file with rspec or cucumber, using colon-separated targets instead of separate commands.

patently blocks must keep local variables inside the block; rebinding an outer variable breaks retries because later attempts reuse the changed value.

BEM-style selectors can be generated from plain-language Cucumber locators, reducing repetitive typing when mapping readable step text to CSS classes.

Cucumber docstrings break when nested triple double quotes appear inside the text; escaping or a Transform can preserve embedded quote markers.

Cucumber factory now infers the model class from the factory, so steps can use natural names like admin instead of user (admin).

Clicking elements by raw CSS selector is brittle; selector_for lets feature steps use plain English names like sidebar instead.

Run Sidekiq jobs synchronously in development to avoid a separate worker process and benefit from code reloading.

Rails JSON serializes times with milliseconds, so iso8601 and to_json can differ in RSpec expectations. Using to_json keeps time string comparisons matching.

Threaded web server benchmark can exhaust application resources more effectively than ApacheBench or httperf; libev is required for installation.

Capybara and Cucumber can verify that a select box includes a disabled choice, using an XPath check on the matching option element.

CucumberFactory 1.11 adds support for FactoryGirl traits, letting Cucumber steps create records with named variations such as vintage and moody.

RSpec example groups and shared examples can use symbols as names, even though the official docs do not mention it.

Mock expectations in RSpec can linger across examples; resetting a proxy removes the configured doubles and returns the object to its original state.

Gem for instantly showing failing specs while continuing to run the rest of the suite, instead of aborting on the first failure.

Using Consul’s authorization matcher with RSpec 2.x on Rails 3.x can fail because of version incompatibilities. Compatibility requires adapting the matcher setup.

Capybara and selenium-webdriver version mismatches can break element interaction with a private select method error. Aligning gem versions avoids the API incompatibility.

Polymorphic associations in Cucumber Factory require named associations; indirect references like owner above fail when the target type is ambiguous.

hash_including in WebMock v3.0.1 compares query values as strings, so integer expectations fail unless the request matcher uses '1' instead of 1.

Copy a single MySQL table between deployment stages by dumping it from one database and importing it into another; imports overwrite existing tables, not merge them.

Tight should_receive(...).with(...) expectations on hashes are brittle and produce unreadable failures. Block-based argument checks keep RSpec assertions clearer and more flexible.

datetime_select creates a clumsy date and time chooser in Rails; a visual picker is usually better, but a Cucumber step can still drive it.

Useful Cucumber steps help inspect a Capybara session by opening the current page in a browser or starting an interactive debugger.