rspec测试比Rails控制台慢得多

Question

I've been spending all day trying to figure out why my rspec-rails test suite takes a really long time to complete (it wasn't always this way) I've used the --profile to determine which tests are taking a long time, and it seems that every test hits the Database takes 30 seconds per query.

Take the following example line:

MyModel.create(args)

If I run this line in the rails console it completes instantaneously, but if I include it in an rspec test, it adds 30 seconds to that test's completion time. Also, this line is only an example, if I use Factory girl or create a relation using << the same 30 second tax seems to apply.

Surely something must be configured wrong.

Heres my spec_helper.rb file:

require 'simplecov'
require 'metric_fu/metrics/rcov/simplecov_formatter'
SimpleCov.formatter = SimpleCov::Formatter::MetricFu
SimpleCov.start 'rails'

# This file is copied to spec/ when you run 'rails generate rspec:install'
ENV["RAILS_ENV"] ||= 'test'
require File.expand_path("../../config/environment", __FILE__)
require 'rspec/rails'
require 'database_cleaner'
require 'carrierwave'

Dir[Rails.root.join("spec/support/**/*.rb")].each {|f| require f}

ActiveRecord::Migration.maintain_test_schema!

RSpec.configure do |config|
  config.fixture_path = "#{::Rails.root}/spec/fixtures"
  config.use_transactional_fixtures = true
  config.infer_base_class_for_anonymous_controllers = false
  config.order = "random"
  config.mock_with :rspec
  config.include JsonSpec::Helpers
  config.include FactoryGirl::Syntax::Methods
  config.include Devise::TestHelpers, type: :controller

  # config.raise_errors_for_deprecations!
  config.infer_spec_type_from_file_location!

  config.expect_with :rspec do |c|
    c.syntax = [:should, :expect]
  end

  config.before(:suite) do
    begin
      EphemeralResponse.activate
      DatabaseCleaner.strategy = :truncation
      DatabaseCleaner.clean_with(:truncation)
      DatabaseCleaner.start
      # FactoryGirl.lint
    ensure
      DatabaseCleaner.clean
    end
  end

  config.before(:each) do
    Bullet.start_request if Bullet.enable?
  end

  config.after(:each) do
    if Bullet.enable? #&& Bullet.notification?
      # Bullet.perform_out_of_channel_notifications
      # Bullet.end_request
    end
    DatabaseCleaner.clean
  end

  config.after(:suite) do
    EphemeralResponse.deactivate
  end
end

I don't really understand a whole lot about rspec, and I didn't write a good portion of this test suite, so maybe this is really obvious to someone, but I've been beating my head against it all day.

Edit: I'm going to add one of my model tests: This one takes over 5 minutes to run...

require 'spec_helper'
describe CourseAssignment do

    let(:instructor) { create(:instructor) }
    let(:student) { create(:student, id: 2) }
    let(:bundle) { create(:bundle) }
    let(:course) { create(:course) }
    let(:assignment) { create(:course_assignment, course: course) }

    it { should belong_to(:course) }
    it { should belong_to(:user) }

    describe 'CourseAssignment deletion' do
        it 'should not delete the Course or the Student' do
      instructor.courses << course # 30 seconds
      instructor.courses.last.students << student # 30 seconds
      CourseAssignment.create(course_id: course.id, user_id: student.id) # 30 seconds
      expect{CourseAssignment.last.destroy}.to change(CourseAssignment, :count).by(-1)
      expect(Student.count).to eq(1)
      expect(Course.count).to eq(1)
      expect(instructor.courses).to include(course)
        end
    end

    describe 'Student deletion' do
        it 'should delete the CourseAssignment & Student, but not the  Course' do
      instructor.courses << course # 30 seconds
      instructor.courses.last.students << student # 30 seconds
      CourseAssignment.create(course_id: course.id, user_id: student.id) # 30 seconds
      expect(student.course_assignments.count).to eq(2)

      expect{student.destroy}.to change(CourseAssignment, :count).by(-2)
      expect(Course.last.students).to be_empty
      expect(Course.count).to eq(1)
      expect(instructor.courses).to include(course)
        end
    end

    describe 'Course deletion' do
        it 'should delete the CourseAssignment' do
      instructor.courses << course # 30 seconds
      instructor.courses.last.students << student # 30 seconds
      CourseAssignment.create(course_id: course.id, user_id: student.id)

      expect{course.destroy}.to change(Course, :count).by(-1)
      expect(CourseAssignment.count).to be(0)
      instructor.reload
      expect(instructor.courses).to be_empty
        end
    end

    it 'should require a course_id' do
        no_course_id_assignment = CourseAssignment.create(course_id: '', user_id: 2) # 30 seconds
        no_course_id_assignment.should_not be_valid
    end

    it 'should require a user_id' do
        no_student_id_assignment = CourseAssignment.create(course_id: 2, user_id: '') # 30 seconds
        no_student_id_assignment.should_not be_valid
    end

end

EDIT 2: I figured out that this has something to do with my computer (Mac os x 10.10.5). When I run our test suite on circle ci it the whole suite runs in less than 5 minutes.

Edit 3: Heres my database.yml

# MySQL.  Versions 4.1 and 5.0 are recommended.
#
# Install the MySQL driver:
#   gem install mysql2
#
# And be sure to use new-style password hashing:
#   http://dev.mysql.com/doc/refman/5.0/en/old-client.html
development:
  adapter: mysql2
  encoding: utf8
  database: xxxx
  username: xxxx
  password: xxxx
  host: localhost

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  adapter: mysql2
  encoding: utf8
  database: xxxx_test
  username: xxxx
  password: xxxx
  host: localhost

production:
  adapter: mysql2
  encoding: utf8
  host: localhost
  database: xxxx
  username: xxxx
  password: xxxx
  port: 3306

Edit 4: Just figured out that changing my wifi network fixes the issue. The problem seems to be related to an outage associated with the first network where mixpanel.com is unreachable.

Answer 1

When you execute rails c , note that it takes some time to load since it is starting up the DB and loading Rails classes which will be available "instantly".

Each test spec recreates a clean DB slate each time, so it should take more time than running the same command in the console (because the DB is already set up). You can mitigate this by correctly using before(:all) and setting up tests in such a way that the the same instance is used as much as possible without needing a clean slate.