rspec unit testing a method which has a infinite loop

Question

I have a method like this

class SomeClass
  def self.test_method
    while(true)
      make_heavy_lifting
      sleep(60*60)
    end
  end
end

How do i write test for this method.

one solution i thought of is stubbing sleep method and it worked but i am not able to stub the while keyword. please suggest best practices for unit testing a method which has infinite loop.

score 6 · Accepted Answer · edited May 23 '17 at 11:46

6

Maybe you can move everything inside the while except the sleep to another method, then you write specs only for that method, I don't think you really need to test that your method has a while loop and a sleep (you don't need to test EVERY line of your code :P) but if you want to do that check this question, it has some things you can try What is the best practice when it comes to testing "infinite loops"?

edited May 23 '17 at 11:46

Community

1
1

answered Nov 13 '12 at 18:01

arieljuod

15,460
2
25
36

Agreed. but i was hoping is there any way to stub the while(true) keyword. if its not then i have to separate the logic out of it. – Sharath B. Patel Nov 14 '12 at 06:33

score 5 · Answer 2 · edited May 23 '17 at 12:02

To test this I stub :loop and use that instead of while(true):

class:

class SomeClass
  def self.test_method
    loop do
      make_heavy_lifting
      sleep(60*60)
    end
  end
end

spec:

describe SomeClass do
  describe '#test_method' do
    expect(SomeClass).to receive(:loop).and_yield
    expect(SomeClass).to receive(:make_heavy_lifting)
    expect(SomeClass).to receive(:sleep).with(60*60)
end

this way it will only iterate through it once.

EDIT: it seems this was also suggested in the other question

rspec unit testing a method which has a infinite loop

2 Answers2