[Rspec] Efficiently Speed Rspec test

參考第一篇文章

author has deleted
~~https://medium.com/the-code-review/5-rspec-tips-to-speed-up-testing-ruby-on-rails-projects-db8759a20869~~

Conclusion
前面 1 ~ 4 點，學習一些技巧和寫法，但是效能提升没特別提到
但文章的第 5 點 Efficiently load data records 得到几个方向

Use let, rather than let!
One is to use before_all instead of before_each in a test file
Another is to have a global variables file, which loads an instance of each record before all tests start
Another approach is to user FactoryBot’s build_stubbed method

參考第二篇文章

http://breazeal.com/blog/jasmineBefore.html
https://stackoverflow.com/questions/16617052/rails-rspec-before-all-vs-before-each

Conclusion

Always we write this for each example

1
2
3

before(:each) do
   ....
end

Maybe can use this to do only 1 query and 1 times insert to DB

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2
3

before(:all) do
    .....
end

參考第三篇文章

https://engineers.sg/video/speeding-up-your-test-suite-reddotrubyconf-2016--808
from ruby conference

影片

Conclusion

Absolutely point to 5 steps to save time
7 examples from 22 sec down to 3 sec

Can use Zeus or Spring to save time.
Yesterday which I read also mention this:

http://www.betterspecs.org/zh_tw/#spork

5 steps to follow:

(1) Measure test performance often and efficiently (now only 15 sec)
use Zeus | Spring, Rspec profile

(2) Avoid forceful database clean after each test (now only 7 sec, compare before save 47%)

bad:

config.before(:each) do
    DatabaseCleaner.start
end
config.after(:each) do
    DatabaseCleaner.clean
end

good:

config.before(:all) do
    DatabaseCleaner.start
end
config.after(:all) do
    DatabaseCleaner.clean
end

(3) Declare and reuse associations (now only 5 sec, compare before save 40%)

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2
3

before(:all) do
  @user = FactoryGirl.create(:user)
end

Reuse in object declaration

before(:each) do
  @order_fulfillment = FactoryGirl.create(
    :order_fulfillment,
    user: @user,
    order: @order,
    shoper:@user
end

(4) Use build stubbed, until you can’t (now only 4.8 sec, compare before save 4%)
FactoryGirl’s build strategied

create
build
build stubbed

before(:each) do
  @order_fulfillment = FactoryGirl.build_stubbed(
    :order_fulfillment,
    user: @user,
    order: @order,
    shoper:@user
end

(5) Use mocks and stubs to imitate slow operations (now only 3 sec, compare before save 38%)

before do
  allow(FeatureToggles::GeeTest).
  to receive(:disabled?).
  and_return(false)
  allow_any_instance_of(Captcha::GeeTest).
  to receive(:validate!).
  and_raise(Captcha::GeeTest::Error.new("Captcha Validation Failed"))
end