---

name: test-gen description: Generate comprehensive Minitest suites for Rails models and controllers. Use when user wants to add tests, improve coverage, fill empty test files, or says "test [model/controller]", "add tests", "write tests for", "test coverage", "generate tests".

Test Generator

Fill empty test files with comprehensive Minitest suites based on existing code.

Quick Start

CopyTask Progress (copy and check off):
- [ ] 1. Analyze model/controller code
- [ ] 2. Generate association tests
- [ ] 3. Generate validation tests
- [ ] 4. Generate enum/scope tests
- [ ] 5. Generate controller CRUD tests
- [ ] 6. Create realistic fixtures
- [ ] 7. Add test helpers
- [ ] 8. Run tests and verify

Current State

All test files are empty stubs. This skill transforms them into working test suites.

Copy# Current state
class UserTest < ActiveSupport::TestCase
  # test "the truth" do
  #   assert true
  # end
end

Generation Strategy

1. Read the model/controller to identify:

   • Associations
   • Validations
   • Enums
   • Scopes
   • Instance methods
   • Controller actions

2. Generate tests for each element found

3. Create fixtures with valid, realistic data

4. Run tests to verify they pass

Test Patterns

See detailed examples:

• Models: examples/model_tests.md
• Controllers: examples/controller_tests.md
• Fixtures: examples/fixture-patterns.md
• Scripts: run_tests.sh, generate_fixtures.rb

Quick Examples

Association test:

Copytest "should belong to user" do
  post = posts(:one)
  assert_instance_of User, post.user
end

Validation test:

Copytest "should validate presence of title" do
  post = Post.new
  assert_not post.valid?
  assert_includes post.errors[:title], "can't be blank"
end

Enum test:

Copytest "should transition between statuses" do
  post = posts(:one)
  post.draft!
  assert post.draft?

  post.published!
  assert post.published?
end

Controller authorization test:

Copytest "should not update when unauthorized" do
  log_in_as users(:two)
  patch post_path(@post), params: { post: { title: "Hacked" } }

  assert_redirected_to root_path
  assert_not_equal "Hacked", @post.reload.title
end

Fixture Pattern

Copyone:
  user: one
  email: user1@example.com
  password_digest: <%= BCrypt::Password.create('password', cost: 4) %>
  name: Test User One
  created_at: <%= 2.days.ago %>

Key points:

• BCrypt cost 4 for faster tests
• Valid associations
• Realistic data
• Proper timestamps

Test Helper

Add to test/test_helper.rb:

Copydef log_in_as(user)
  session[:user_id] = user.id
end

Coverage Goals

• Core models (User, Post): 90%+
• Feature models (JobPost, Comment): 85%+
• Simple models (Like, Bookmark): 80%+

After Generation

Copy# Run all tests
rails test

# Run specific file
rails test test/models/user_test.rb

# With coverage (if SimpleCov installed)
COVERAGE=true rails test

Common Test Types

For models:

• Associations
• Validations (presence, format, uniqueness, length)
• Enums (transitions, i18n)
• Scopes (ordering, filtering)
• Instance methods
• Counter caches

For controllers:

• Index (public access)
• Show (public access, view increment)
• New/Create (require login, authorization)
• Edit/Update/Destroy (require ownership)
• Invalid data handling
• Flash messages

Project Patterns

From existing codebase:

• Use Minitest (not RSpec)
• Use Fixtures (not FactoryBot)
• Flash messages in Korean
• Auth via session[:user_id]
• BCrypt cost 4 in fixtures
• ActiveSupport::TestCase for models
• ActionDispatch::IntegrationTest for controllers

Checklist

• All associations tested
• All validations tested (valid + invalid cases)
• Enum transitions tested
• Scopes tested
• Controller auth tested
• CRUD operations tested
• Fixtures have realistic data
• Test helper methods added
• All tests pass
• Coverage >= 80%