### Contribution: Setup and Run Tests

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Commands to set up the development environment and run the test suite locally. This includes installing dependencies, updating appraisal configurations, and executing tests against various Rails versions.

```shell
$ bundle install
$ bundle exec appraisal update
$ bundle exec appraisal rake test
```

```shell
$ bundle exec appraisal rails_v6.0.x rake test
$ bundle exec appraisal rails_v6.1.x rake test
$ bundle exec appraisal rails_v7.0.x rake test
```

--------------------------------

### Setup and Teardown Compatibility

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Shows how minitest-spec-rails supports multiple setup and teardown methods, including those defined by symbols or blocks, which are evaluated in the instance scope, similar to standard ActiveSupport callbacks.

```Ruby
class ActiveSupportCallbackTest < ActiveSupport::TestCase

  setup :foo
  setup :bar
  before { @bat = 'biz' }

  it 'works' do
    expect(@foo).must_equal 'foo'
    expect(@bar).must_equal 'bar'
    expect(@bat).must_equal 'biz'
  end

  private

  def foo ; @foo = 'foo' ; end
  def bar ; @bar = 'bar' ; end

end
```

--------------------------------

### `mini_shoulda` Usage Example

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Provides an example of using the `mini_shoulda` aliases (`should`, `context`, `should_eventually`) for writing tests, mimicking the syntax of the Shoulda testing framework.

```Ruby
class PostTests < ActiveSupport::TestCase
  setup    { @post = Post.create! :title => 'Test Title', :body => 'Test body' }
  teardown { Post.delete_all }
  should 'work' do
    @post.must_be_instance_of Post
  end
  context 'with a user' do
    should_eventually 'have a user' do
      # ...
    end
  end
end
```

--------------------------------

### Example Minitest::Spec Test Case in Rails

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

A practical example of a test case written using the Minitest::Spec DSL within a Rails application. It demonstrates defining a fixture using `let` and asserting object type.

```ruby
require 'test_helper'
class UserTest < ActiveSupport::TestCase
  let(:user_ken)   { User.create! :email => 'ken@metaskills.net' }
  it 'works' do
    expect(user_ken).must_be_instance_of User
  end
end
```

--------------------------------

### Rails Test Case Subclassing Examples

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Provides examples of how to structure test files for different types of Rails components (Models, Controllers, Integration, Mailers) using appropriate `ActiveSupport::TestCase` subclasses.

```ruby
# Model Test (or anything else not listed below)
class UserTest < ActiveSupport::TestCase
end

# Controller Test
class UsersControllerTest < ActionController::TestCase
end

# Integration Tests - Must use subclass style!
class IntegrationTest < ActionDispatch::IntegrationTest
end

# Mailer Test
class UserMailerTest < ActionMailer::TestCase
end
```

--------------------------------

### Minitest Assertion Style Examples

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Illustrates the interchangeability of Minitest::Unit and Minitest::Spec assertion styles within the same test suite. This allows for gradual migration from older styles.

```ruby
# Minitest::Unit Assertion Style:
assert_equal 100, foo

# Minitest::Spec Assertion Style:
expect(foo).must_equal 100
```

--------------------------------

### Basic Gem Installation for minitest-spec-rails

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

A simple instruction to include the minitest-spec-rails gem in your project's dependencies. This is the most straightforward way to add the gem.

```ruby
gem 'minitest-spec-rails'
```

--------------------------------

### Using `minitest-matchers` Gem

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Demonstrates how to use the `minitest-matchers` gem for writing tests, specifically showing examples of `must have_valid` and `wont have_valid` assertions for attribute validation testing.

```Ruby
describe Post do
  subject { Post.new }
  it { must have_valid(:title).when("Hello") }
  it { wont have_valid(:title).when("", nil, "Bad") }
end
```

--------------------------------

### Using `described_class` Helper

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Illustrates the `described_class` helper method, available as both a class and instance method, which returns the class currently being tested. It works across nested describe blocks, provided Rails naming conventions are followed.

```Ruby
class UserTest < ActiveSupport::TestCase
  described_class # => User(id: integer, email: string)
  it 'works here' do
    described_class # => User(id: integer, email: string)
  end
  describe 'and' do
    it 'works here too' do
      described_class # => User(id: integer, email: string)
    end
  end
end
```

--------------------------------

### Basic Minitest Test Cases

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Demonstrates the basic structure for defining test cases using Minitest with Rails-specific test classes like ActionView::TestCase and ActiveJob::TestCase.

```Ruby
class UsersHelperTest < ActionView::TestCase
end

class MyJobTest < ActiveJob::TestCase
end
```

--------------------------------

### Enabling `mini_shoulda` Feature

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Demonstrates how to enable the `mini_shoulda` feature in `config/environments/test.rb` to gain aliases for Shoulda's `context`, `should`, and `should_eventually` methods, facilitating migration from Shoulda.

```Ruby
# In config/environments/test.rb
config.minitest_spec_rails.mini_shoulda = true
```

--------------------------------

### Replacing Shoulda Assertions with Minitest

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Shows common patterns for replacing Shoulda assertion methods with their Minitest equivalents, advocating for modern Minitest syntax over older assertion styles.

```Ruby
assert_same_elements a, b         # From
expect(a.sort).must_equal b.sort  # To

assert_does_not_contain a, b  # From
expect(a).wont_include b      # To
```

--------------------------------

### Using `minitest-matchers-vaccine` Gem

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Illustrates the usage of the `minitest-matchers-vaccine` gem, which provides similar assertion capabilities to `minitest-matchers` but aims to avoid polluting tested objects.

```Ruby
describe User do
  subject { User.new }
  it "should validate email" do
    must have_valid(:email).when("a@a.com", "foo@bar.com")
    wont have_valid(:email).when(nil, "", "foo", "foo@bar")
  end
end
```

--------------------------------

### Add minitest-spec-rails Gem for Rails 4.1 to 6.0

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

This snippet shows how to add the minitest-spec-rails gem to your Rails application's Gemfile for versions 4.1 through 6.0. It's placed within the `:test` group.

```ruby
group :test do
  gem 'minitest-spec-rails'
end
```

--------------------------------

### Disable Mocha Deprecation Warnings

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Configures Mocha to disable deprecation warnings, ensuring compatibility with newer Minitest versions. This snippet should be placed in `application.rb` after `require 'rails/all'`.

```ruby
require 'mocha/deprecation'
Mocha::Deprecation.mode = :disabled
```

--------------------------------

### Add minitest-spec-rails Gem for Rails 3.x or 4.0

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

This snippet demonstrates how to add a specific version of the minitest-spec-rails gem to your Rails application's Gemfile for compatibility with Rails 3.x or 4.0. It targets the '~> 4.7' version.

```ruby
group :test do
  gem 'minitest-spec-rails', '~> 4.7'
end
```

--------------------------------

### Rails 3.0 Controller/Mailer Test Interface

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Specifies the `tests` interface for controller and mailer tests in Rails 3.0.x. This is a workaround for a potential `class_attribute` bug in Rails 3.0, ensuring assertions are correctly set up within sub `describe` blocks.

```ruby
class UsersControllerTest < ActionController::TestCase
  tests UsersController
end

class UserMailerTest < ActionMailer::TestCase
  tests UserMailer
end
```

--------------------------------

### Minitest Assertion Renaming

Source: https://github.com/metaskills/minitest-spec-rails/blob/master/README.md

Highlights assertion method renames when migrating from Test::Unit to Minitest, specifically noting `assert_raise` becoming `assert_raises` and the absence of `assert_nothing_raised`.

```Ruby
# Renamed: assert_raise -> assert_raises
# Removed: assert_nothing_raised
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.