Ruby
Rails ships with a testing framework built in. Most teams either use it as-is (Minitest) or replace it with RSpec. Both are solid choices, but they have different philosophies and different ecosystems. This guide covers what you need to know to test a Rails application effectively — regardless of which
Ruby
System tests are the closest thing to a real user clicking through your application. They drive a browser, fill in forms, click buttons, and assert what the user sees. Rails has built-in support for system tests via Capybara, and this guide covers how to use them effectively. What System
Testing
Since Rails 6, parallel test execution is built into the framework — no third-party gems required. One method call in your test helper can turn a 10-minute test suite into a 2-minute run. This guide covers the setup, database isolation, and the operational details that matter for CI.
Ruby on Rails
Rails request specs are the right tool for testing APIs—they exercise the full stack from routing through serialization without a real browser. This post covers JSON assertion patterns, authentication header strategies, API versioning in tests, and shared helpers that keep API specs readable and maintainable. Rails provides three layers
Ruby
Testing a Rails API is one of the highest-leverage testing activities in a Rails application. A well-tested API means consumers — mobile apps, frontend SPAs, third-party integrations — can rely on consistent behavior. Request specs are the right tool for this job. Why Request Specs for APIs Rails provides
Testing
Background jobs are notoriously undertested. They run asynchronously, fail silently, and interact with external services — all the characteristics that make testing uncomfortable. Rails ActiveJob provides testing tools that make job testing as straightforward as controller testing, without requiring a running queue worker. Queue Adapter Configuration Set the queue adapter to
Testing
Email is one of the most undertested parts of Rails applications. Bugs in welcome emails, password resets, and notifications often slip through because developers don't know how to write email tests efficiently. Rails makes it straightforward — the test mailbox captures every email sent during tests, and both RSpec
Ruby on Rails
Capybara system tests exercise your Rails app through a real browser, catching integration bugs that unit and controller tests miss entirely. This post covers driver selection (Selenium vs Cuprite), async JavaScript patterns, screenshot-on-failure setup, and scoping techniques for complex UIs. System tests are the most expensive tests to
Ruby
Tests that make real HTTP requests are slow, flaky, and dependent on external services staying available. VCR and WebMock solve this by intercepting HTTP requests and either returning pre-recorded responses or raising errors when unexpected network calls happen. This guide covers both tools, when to use each, and how
Ruby
Rails system tests let you test your application through a real browser, exercising JavaScript, authentication flows, and multi-step user interactions that unit tests cannot reach. They use Capybara as the test DSL and Selenium WebDriver to control Chrome or Firefox. This guide covers writing effective system tests, handling JavaScript
Ruby
Rails APIs need a different testing approach than HTML applications. There's no browser to drive, no UI interactions — just HTTP requests and JSON responses. RSpec request specs are the right tool: they test the full request/response cycle through Rack middleware without the overhead of a browser. This
Ruby
Minitest ships with Ruby's standard library and powers the default test suite in every new Rails application. It's fast, minimal, and surprisingly capable. Many teams that start with RSpec eventually migrate back to Minitest for its simplicity and performance. This guide covers everything you need to