rspec-testing

# RSpec Testing for Rails

## Overview

Write comprehensive, maintainable RSpec tests following industry best practices. This skill combines guidance from Better Specs and thoughtbot's testing guides to produce high-quality test coverage for Rails applications.

## Core Testing Principles

### 1. Test-Driven Development (TDD)
Follow the Red-Green-Refactor cycle:
- **Red**: Write failing tests that define expected behavior
- **Green**: Implement minimal code to make tests pass
- **Refactor**: Improve code while tests continue to pass

### 2. Test Structure (Arrange-Act-Assert)
Organize tests with clear phases separated by newlines:

```ruby
it 'creates a new article' do
  # Arrange - set up test data
  user = create(:user)
  attributes = {title: 'Test Article', body: 'Content here'}

  # Act - perform the action
  article = Article.create(attributes)

  # Assert - verify the outcome
  expect(article).to be_persisted
  expect(article.title).to eq('Test Article')
end
```

### 3. Single Responsibility
Each test should verify one behavior. For unit tests, use one expectation per test. For integration tests, multiple expectations are acceptable when testing a complete flow.

### 4. Test Real Behavior
Avoid over-mocking. Test actual application behavior when possible. Only stub external services, slow operations, and dependencies outside your control.

## Test Type Decision Tree

### When to Write Model Specs
Use model specs (`spec/models/`) for:
- Validations
- Associations
- Scopes
- Instance methods
- Class methods
- Enums and constants
- Database constraints

**Example:**
```ruby
# spec/models/article_spec.rb
RSpec.describe Article do
  describe 'validations' do
    it 'validates presence of title' do
      article = build(:article, title: nil)
      expect(article).not_to be_valid
      expect(article.errors[:title]).to include("can't be blank")
    end
  end

  describe 'associations' do
    it { is_expected.to belong_to(:user) }
    it { is_expected.to have_many(:co