Having troubles with expect_any_instance_of behavior? How to expect n number of times a method is invoked?

16 Aug Having troubles with expect_any_instance_of behavior? How to expect n number of times a method is invoked?

In case you are having troubles to use the

expect_any_instance_of

From Rspec, guess what, it is not only you, many of us have faced the same troubles before, you can see it here in the thread discussion
https://github.com/rspec/rspec-mocks/issues/910

I really agree with this argument:

The name of the method is “expect_any_instance_of” so I would expect this to mean that any instance could receive it. Instead, you’ve implemented it so that it refers to a single instance. So really, “expect_any_instance_of” actually means “expect_exactly_one_instance_of” and the name “expect_any_instance_of” is deceptive in my opinion and a violation of the Principle of Least Surprise.

So, to make the long story short here is what I ended up, thanks to the last comment by MaxPleaner

I have a class that makes a retry to the database let’s say

class InvoiceFinder
  def self.find_with_retry
     tries = 2
     time_span_start = Time.zone.now
     loop do
       params = { user_ids: user_ids, start: time_span_start }
       invoices = InvoceQuery.new(params).upcoming_invoices
       if(invoices.present? || tries <= 0
         break
       else
         time_span_start += 5.days
         tries -= 1
       end
     end
      
     invoices
  end
end

In order to make sure the retry works we could have some Rspec just like this:

context 'when there is more than 1 retry from the database' do
  before do
    @counting_executions = 0
    allow_any_instance_of(InvoceQuery).to receive(:upcoming_invoices) do
      @counting_executions += 1
      []
    end
  end

  it 'makes three retries to get data from the databases' do
    InvoiceFinder.find_with_retry
    expect(@counting_executions).to eq 3
  end
end

There you, let me know any comments and thoughts, have you used any other strategy to test these sort of scenarios?
Keep learning, coding and relax.

H.