# Minitest — Complete Testing Suite for Ruby

> Minitest provides a complete suite of testing facilities for Ruby, supporting TDD, BDD, mocking, and benchmarking in a fast, lightweight package bundled with Ruby itself.

## Install

Save in your project root:

# Minitest — Complete Testing Suite for Ruby

## Quick Use
```ruby
# test/test_calculator.rb
require "minitest/autorun"

class TestCalculator < Minitest::Test
  def test_addition
    assert_equal 4, 2 + 2
  end
end

# Run: ruby test/test_calculator.rb
```

## Introduction
Minitest is Ruby's built-in testing framework, shipping with every Ruby installation since 1.9. It provides a clean, fast alternative to larger testing libraries while supporting unit tests, specs, mocks, and benchmarks in a single package under 1,500 lines of code.

## What Minitest Does
- Provides assert-style unit testing with Minitest::Test
- Supports RSpec-like describe/it syntax with Minitest::Spec
- Includes a built-in mock and stub system for test doubles
- Offers benchmarking capabilities for performance testing
- Ships with Ruby so no additional gem installation is required

## Architecture Overview
Minitest is a single-gem library with modular components. The core runner discovers test classes, shuffles test order for isolation, and executes each method. Results are collected by a reporter pipeline that can output dots, verbose names, or custom formats. The spec DSL is a thin wrapper that generates Minitest::Test subclasses at load time.

## Self-Hosting & Configuration
- Already included with Ruby; optionally pin a version in your Gemfile
- Place test files in a test directory following the test_*.rb naming convention
- Configure reporters and plugins via Minitest.extensions
- Use Minitest::Spec for BDD-style syntax if preferred
- Integrate with Rake by defining a Rake::TestTask in your Rakefile

## Key Features
- Ships with Ruby, requiring zero setup for new projects
- Extremely fast execution due to minimal overhead
- Randomized test order by default to catch order dependencies
- Extensible plugin system for custom reporters and assertions
- Spec DSL provides familiar describe/it syntax without switching frameworks

## Comparison with Similar Tools
- **RSpec** — full-featured BDD framework with extensive DSL; Minitest is leaner and faster with optional spec syntax
- **Test::Unit** — older Ruby testing library; Minitest is its modern successor bundled with Ruby
- **Cucumber** — acceptance testing with Gherkin syntax; Minitest focuses on unit and integration tests
- **pytest** — Python testing framework; Minitest fills the same role for the Ruby ecosystem
- **Jest** — JavaScript testing with snapshots; Minitest serves Ruby with similar assertion-based patterns

## FAQ
**Q: Should I use Minitest or RSpec?**
A: Minitest is faster and simpler with less magic. RSpec offers a richer DSL and ecosystem. Both are production-ready choices.

**Q: Can I use Minitest with Rails?**
A: Yes, Rails includes Minitest as its default testing framework with generators for test files.

**Q: How do I add custom assertions?**
A: Define methods in a module and include it in Minitest::Test. Custom assertions follow the assert_* naming convention.

**Q: Does Minitest support parallel test execution?**
A: Yes, use Minitest.parallel_executor to run test classes in threads, or use the parallelize method in Rails.

## Sources
- https://github.com/minitest/minitest
- https://docs.seattlerb.org/minitest

---
Source: https://tokrepo.com/en/workflows/asset-47c109e2
Author: AI Open Source