ruby
Fixtures or factories for Rails tests? How each approach works: static YAML data Rails loads before every run versus FactoryBot objects built on demand, with examples and clear guidance on when speed favors fixtures and flexibility favors factories.
ruby
FactoryBot traits can nest other traits, letting you compose reusable test fixtures instead of copying attribute blocks. A quick refresher on traits, then the traitception pattern: defining traits inside traits and combining them for cleaner Rails test setup.
minitest
Slow test suites usually hide a few expensive tests. Minitest and RSpec both ship a built-in profiler: bin/rails test --profile and rspec --profile 10 list your slowest examples with execution times, so you know exactly which tests to optimize first.