How to test that private method is called using rspec

Question

I'm trying to make sure that a given method is being called when called by a callback. Basically, I have a RiskMatrix model, that calls 2 private methods on callback after_save So I'm trying to test that those methods are properly called.

thanks a lot for your help

class RiskMatrix < ActiveRecord::Base
   after_save :alert_admin, :save_suspicious_ip, if: proc {score.length >= ALERT_THRESHOLD}

    private
    def alert_admin
        [...]
    end

    def save_suspicious_ip
        [...]
    end
end

risk_matrix_spec.rb

 describe 'after_save' do
  context 'score.length > ALERT_THRESHOLD' do
    it 'should run alert_admin' do
      matrix = build(:risk_matrix, score: 'ABCD')
      expect(matrix).to receive(:alert_admin)
    end

    it 'should run save_suspicious_ip' do
      matrix = create(:risk_matrix, score: 'ABCD')
      expect(matrix).to receive(:save_suspicious_ip)
    end

  end
end

both tests fail

 (#<RiskMatrix id: 3201, score: "ABCD", user_id: 3115, created_at: "2019-02-05 16:27:01", updated_at: "2019-02-05 16:27:01">).alert_admin(*(any args))
    expected: 1 time with any arguments
    received: 0 times with any arguments

    (#<RiskMatrix id: nil, score: "ABCD", user_id: nil, created_at: nil, updated_at: nil>).save_suspicious_ip(*(any args))
    expected: 1 time with any arguments
    received: 0 times with any arguments

From my point of view this should answer your question https://stackoverflow.com/a/42293469/7654691 — R. Sierra, Feb 05 '19 at 18:54

score 3 · Answer 1 · answered Feb 05 '19 at 19:34

You can use shoulda-callback-matchers to test your callbacks

it { is_expected.to callback(:alert_admin).after(:save) }

The other way to test is verify that after save a matrix a suspicious_ip must exist.

let(:matrix) { create(:risk_matrix, score: 'ABCD') }
context "when score.length > ALERT_THRESHOLD" do
  it "after create a matrix" do
   expect(matrix.suspicious_ip).to_not be_nil
  end
end
context "when score.length < ALERT_THRESHOLD" do
  it "after create a matrix" do
   expect(matrix.suspicious_ip).to be_nil
  end
end

thanks a lot! I've tried the gem works great except for conditional callbacks. — Mike W, Feb 06 '19 at 13:05

score 1 · Answer 2 · answered Feb 12 '19 at 13:09

Maybe I am missing something but I am not seeing the save calls, have you tried:

it 'should run alert_admin' do
  matrix = build(:risk_matrix, score: 'ABCD')
  allow(matrix).to receive(:alert_admin)
  matrix.save!
  expect(matrix).to have_received(:alert_admin).once
end

Before you save you let RSpec know you gonna stub that method, after the save you verify the method was called.

How to test that private method is called using rspec

2 Answers2