Rails 指南

$ ls -F test
controllers/           helpers/               mailers/               system/                test_helper.rb
fixtures/              integration/           models/                application_system_test_case.rb

$ bin/rails generate model article title:string body:text
...
create  app/models/article.rb
create  test/models/article_test.rb
create  test/fixtures/articles.yml
...

require 'test_helper'

class ArticleTest < ActiveSupport::TestCase
  # test "the truth" do
  #   assert true
  # end
end

require 'test_helper'

class ArticleTest < ActiveSupport::TestCase

test "the truth" do
  assert true
end

def test_the_truth
  assert true
end

assert true

test "should not save article without title" do
  article = Article.new
  assert_not article.save
end

$ bin/rails test test/models/article_test.rb:6
Run options: --seed 44656

# Running:

F

Failure:
ArticleTest#test_should_not_save_article_without_title [/path/to/blog/test/models/article_test.rb:6]:
Expected true to be nil or false


bin/rails test test/models/article_test.rb:6



Finished in 0.023918s, 41.8090 runs/s, 41.8090 assertions/s.

1 runs, 1 assertions, 1 failures, 0 errors, 0 skips

test "should not save article without title" do
  article = Article.new
  assert_not article.save, "Saved the article without a title"
end

Failure:
ArticleTest#test_should_not_save_article_without_title [/path/to/blog/test/models/article_test.rb:6]:
Saved the article without a title

class Article < ApplicationRecord
  validates :title, presence: true
end

$ bin/rails test test/models/article_test.rb:6
Run options: --seed 31252

# Running:

.

Finished in 0.027476s, 36.3952 runs/s, 36.3952 assertions/s.

1 runs, 1 assertions, 0 failures, 0 errors, 0 skips

test "should report error" do
  # 测试用例中没有定义 some_undefined_variable
  some_undefined_variable
  assert true
end

$ bin/rails test test/models/article_test.rb
Run options: --seed 1808

# Running:

.E

Error:
ArticleTest#test_should_report_error:
NameError: undefined local variable or method `some_undefined_variable' for #<ArticleTest:0x007fee3aa71798>
    test/models/article_test.rb:11:in `block in <class:ArticleTest>'


bin/rails test test/models/article_test.rb:9



Finished in 0.040609s, 49.2500 runs/s, 24.6250 assertions/s.

2 runs, 1 assertions, 0 failures, 1 errors, 0 skips

$ bin/rails test -b test/models/article_test.rb

test "should report error" do
  # 测试用例中没有定义 some_undefined_variable
  assert_raises(NameError) do
    some_undefined_variable
  end
end

$ bin/rails test test/models/article_test.rb
Run options: --seed 1559

# Running:

..

Finished in 0.027034s, 73.9810 runs/s, 110.9715 assertions/s.

2 runs, 3 assertions, 0 failures, 0 errors, 0 skips

$ bin/rails test test/models/article_test.rb -n test_the_truth
Run options: -n test_the_truth --seed 43583

# Running:

.

Finished tests in 0.009064s, 110.3266 tests/s, 110.3266 assertions/s.

1 tests, 1 assertions, 0 failures, 0 errors, 0 skips

$ bin/rails test test/models/article_test.rb:6 # 运行某一行中的测试

$ bin/rails test test/controllers # 运行指定目录中的所有测试

$ bin/rails test -h
minitest options:
    -h, --help                       Display this help.
    -s, --seed SEED                  Sets random seed. Also via env. Eg: SEED=n rake
    -v, --verbose                    Verbose. Show progress processing files.
    -n, --name PATTERN               Filter run on /regexp/ or string.
        --exclude PATTERN            Exclude /regexp/ or string from run.

Known extensions: rails, pride

Usage: bin/rails test [options] [files or directories]
You can run a single test by appending a line number to a filename:

    bin/rails test test/models/user_test.rb:27

You can run multiple files and directories at the same time:

    bin/rails test test/controllers test/integration/login_test.rb

By default test failures and errors are reported inline during a run.

Rails options:
    -e, --environment ENV            Run tests in the ENV environment
    -b, --backtrace                  Show the complete backtrace
    -d, --defer-output               Output test failures and errors after the test run
    -f, --fail-fast                  Abort test run on first failure or error
    -c, --[no-]color                 Enable color in the output

# lo & behold! I am a YAML comment!
david:
  name: David Heinemeier Hansson
  birthday: 1979-10-15
  profession: Systems development

steve:
  name: Steve Ross Kellock
  birthday: 1974-09-27
  profession: guy with keyboard

# In fixtures/categories.yml
about:
  name: About

# In fixtures/articles.yml
first:
  title: Welcome to Rails!
  body: Hello world!
  category: about

<% 1000.times do |n| %>
user_<%= n %>:
  username: <%= "user#{n}" %>
  email: <%= "user#{n}@example.com" %>
<% end %>

# 返回 david 固件对应的 User 对象
users(:david)

# 返回 david 的 id 属性
users(:david).id

# 还可以调用 User 类的方法
david = users(:david)
david.call(david.partner)

# 返回一个数组，包含 david 和 steve 两个固件
users(:david, :steve)

$ bin/rails generate test_unit:model article title:string body:text
create  test/models/article_test.rb
create  test/fixtures/articles.yml

$ bin/rails generate system_test users
      invoke test_unit
      create test/system/users_test.rb

require "application_system_test_case"

class UsersTest < ApplicationSystemTestCase
  # test "visiting the index" do
  #   visit users_url
  #
  #   assert_selector "h1", text: "Users"
  # end
end

require "test_helper"
require "capybara/poltergeist"

class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
  driven_by :poltergeist
end

require "test_helper"

class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
  driven_by :selenium, using: :firefox
end

$ bin/rails generate system_test articles

invoke  test_unit
create    test/system/articles_test.rb

require "application_system_test_case"

class ArticlesTest < ApplicationSystemTestCase
  test "viewing the index" do
    visit articles_path
    assert_selector "h1", text: "Articles"
  end
end

$ bin/rails test:system

test "creating an article" do
  visit articles_path

  click_on "New Article"

  fill_in "Title", with: "Creating an Article"
  fill_in "Body", with: "Created this article successfully!"

  click_on "Create Article"

  assert_text "Creating an Article"
end

$ bin/rails generate integration_test user_flows
      exists  test/integration/
      create  test/integration/user_flows_test.rb

require 'test_helper'

class UserFlowsTest < ActionDispatch::IntegrationTest
  # test "the truth" do
  #   assert true
  # end
end

$ bin/rails generate integration_test blog_flow

invoke  test_unit
create    test/integration/blog_flow_test.rb

require 'test_helper'

class BlogFlowTest < ActionDispatch::IntegrationTest
  test "can see the welcome page" do
    get "/"
    assert_select "h1", "Welcome#index"
  end
end

test "can create an article" do
  get "/articles/new"
  assert_response :success

  post "/articles",
    params: { article: { title: "can create", body: "article successfully." } }
  assert_response :redirect
  follow_redirect!
  assert_response :success
  assert_select "p", "Title:\n  can create"
end

post "/articles",
  params: { article: { title: "can create", body: "article successfully." } }
assert_response :redirect
follow_redirect!

$ bin/rails generate scaffold_controller article title:string body:text
...
create  app/controllers/articles_controller.rb
...
invoke  test_unit
create    test/controllers/articles_controller_test.rb
...

$ bin/rails generate test_unit:scaffold article
...
invoke  test_unit
create test/controllers/articles_controller_test.rb
...

# articles_controller_test.rb
class ArticlesControllerTest < ActionDispatch::IntegrationTest
  test "should get index" do
    get articles_url
    assert_response :success
  end
end

get :show, params: { id: 12 }, headers: { "HTTP_REFERER" => "http://example.com/home" }

patch update_url, params: { id: 12 }, xhr: true

test "should create article" do
  assert_difference('Article.count') do
    post articles_url, params: { article: { body: 'Rails is awesome!', title: 'Hello Rails' } }
  end

  assert_redirected_to article_path(Article.last)
end

request.headers['Authorization'] = ActionController::HttpAuthentication::Basic.
  encode_credentials('dhh', 'secret')

test "ajax request" do
  article = articles(:one)
  get article_url(article), xhr: true

  assert_equal 'hello world', @response.body
  assert_equal "text/javascript", @response.content_type
end

flash["gordon"]               flash[:gordon]
session["shmession"]          session[:shmession]
cookies["are_good_for_u"]     cookies[:are_good_for_u]

class ArticlesControllerTest < ActionDispatch::IntegrationTest
  test "should get index" do
    get articles_url

    assert_equal "index", @controller.action_name
    assert_equal "application/x-www-form-urlencoded", @request.media_type
    assert_match "Articles", @response.body
  end
end

# 设定一个 HTTP 首部
get articles_url, headers: { "Content-Type": "text/plain" } # 模拟有自定义首部的请求

# 设定一个 CGI 变量
get articles_url, headers: { "HTTP_REFERER": "http://example.com/home" } # 模拟有自定义环境变量的请求

test "should create article" do
  assert_difference('Article.count') do
    post article_url, params: { article: { title: 'Some title' } }
  end

  assert_redirected_to article_path(Article.last)
  assert_equal 'Article was successfully created.', flash[:notice]
end

$ bin/rails test test/controllers/articles_controller_test.rb -n test_should_create_article
Run options: -n test_should_create_article --seed 32266

# Running:

F

Finished in 0.114870s, 8.7055 runs/s, 34.8220 assertions/s.

  1) Failure:
ArticlesControllerTest#test_should_create_article [/test/controllers/articles_controller_test.rb:16]:
--- expected
+++ actual
@@ -1 +1 @@
-"Article was successfully created."
+nil

1 runs, 4 assertions, 1 failures, 0 errors, 0 skips

def create
  @article = Article.new(article_params)

  if @article.save
    flash[:notice] = 'Article was successfully created.'
    redirect_to @article
  else
    render 'new'
  end
end

$ bin/rails test test/controllers/articles_controller_test.rb -n test_should_create_article
Run options: -n test_should_create_article --seed 18981

# Running:

.

Finished in 0.081972s, 12.1993 runs/s, 48.7972 assertions/s.

1 runs, 4 assertions, 0 failures, 0 errors, 0 skips

test "should show article" do
  article = articles(:one)
  get article_url(article)
  assert_response :success
end

test "should destroy article" do
  article = articles(:one)
  assert_difference('Article.count', -1) do
    delete article_url(article)
  end

  assert_redirected_to articles_path
end

test "should update article" do
  article = articles(:one)

  patch article_url(article), params: { article: { title: "updated" } }

  assert_redirected_to article_path(article)
  # 重新加载关联，获取最新的数据，然后断定标题更新了
  article.reload
  assert_equal "updated", article.title
end

require 'test_helper'

class ArticlesControllerTest < ActionDispatch::IntegrationTest
  # 在各个测试之前调用
  setup do
    @article = articles(:one)
  end

  # 在各个测试之后调用
  teardown do
    # 如果控制器使用缓存，最好在后面重设
    Rails.cache.clear
  end

  test "should show article" do
    # 复用 setup 中定义的 @article 实例变量
    get article_url(@article)
    assert_response :success
  end

  test "should destroy article" do
    assert_difference('Article.count', -1) do
      delete article_url(@article)
    end

    assert_redirected_to articles_path
  end

  test "should update article" do
    patch article_url(@article), params: { article: { title: "updated" } }

    assert_redirected_to article_path(@article)
    # 重新加载关联，获取最新的数据，然后断定标题更新了
    @article.reload
    assert_equal "updated", @article.title
  end
end

# test/test_helper.rb

module SignInHelper
  def sign_in_as(user)
    post sign_in_url(email: user.email, password: user.password)
  end
end

class ActionDispatch::IntegrationTest
  include SignInHelper
end

require 'test_helper'

class ProfileControllerTest < ActionDispatch::IntegrationTest

  test "should show profile" do
    # 辅助方法在任何控制器测试用例中都可用
    sign_in_as users(:david)

    get profile_url
    assert_response :success
  end
end

assert_select 'title', "Welcome to Rails Testing Guide"

assert_select 'ul.navigation' do
  assert_select 'li.menu_item'
end

assert_select "ol" do |elements|
  elements.each do |element|
    assert_select element, "li", 4
  end
end

assert_select "ol" do
  assert_select "li", 8
end

assert_select_email do
  assert_select 'small', 'Please click the "Unsubscribe" link if you want to opt-out.'
end

module UserHelper
  def link_to_user(user)
    link_to "#{user.first_name} #{user.last_name}", user
  end
end

class UserHelperTest < ActionView::TestCase
  test "should return the user's full name" do
    user = users(:david)

    assert_dom_equal %{<a href="/user/#{user.id}">David Heinemeier Hansson</a>}, link_to_user(user)
  end
end

require 'test_helper'

class UserMailerTest < ActionMailer::TestCase
  test "invite" do
    # 创建邮件，将其存储起来，供后面的断言使用
    email = UserMailer.create_invite('me@example.com',
                                     'friend@example.com', Time.now)

    # 发送邮件，测试有没有入队
    assert_emails 1 do
      email.deliver_now
    end

    # 测试发送的邮件中有没有预期的内容
    assert_equal ['me@example.com'], email.from
    assert_equal ['friend@example.com'], email.to
    assert_equal 'You have been invited by me@example.com', email.subject
    assert_equal read_fixture('invite').join, email.body.to_s
  end
end

Hi friend@example.com,

You have been invited.

Cheers!

require 'test_helper'

class UserControllerTest < ActionDispatch::IntegrationTest
  test "invite friend" do
    assert_difference 'ActionMailer::Base.deliveries.size', +1 do
      post invite_friend_url, params: { email: 'friend@example.com' }
    end
    invite_email = ActionMailer::Base.deliveries.last

    assert_equal "You have been invited by me@example.com", invite_email.subject
    assert_equal 'friend@example.com', invite_email.to[0]
    assert_match(/Hi friend@example.com/, invite_email.body.to_s)
  end
end

require 'test_helper'

class BillingJobTest < ActiveJob::TestCase
  test 'that account is charged' do
    BillingJob.perform_now(account, product)
    assert account.reload.charged_for?(product)
  end
end

require 'test_helper'

class ProductTest < ActiveJob::TestCase
  test 'billing job scheduling' do
    assert_enqueued_with(job: BillingJob) do
      product.charge(account)
    end
  end
end

# 假设用户在注册一个月内可以获取礼品
user = User.create(name: 'Gaurish', activation_date: Date.new(2004, 10, 24))
assert_not user.applicable_for_gifting?
travel_to Date.new(2004, 11, 24) do
  assert_equal Date.new(2004, 10, 24), user.activation_date # 在 travel_to 块中， `Date.current` 是拟件
  assert user.applicable_for_gifting?
end
assert_equal Date.new(2004, 10, 24), user.activation_date # 改动只在 travel_to 块中可见