allow_any_instance_of to count up the number of method calls across different instances

rspec_any_instance_count.rb

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  gem 'rspec', '~> 3.0'
end

require 'rspec/autorun'

RSpec.describe 'test', type: :model do

  class Hoge
    def hoge; end
  end
  describe 'Hoge' do
    it 'raise error with exactly matcher' do
      expect_any_instance_of(Hoge).to receive(:hoge).exactly(1).times

      Hoge.new.hoge
      expect { Hoge.new.hoge }.to raise_error(/The message 'hoge' was received by #<Hoge:.+>/)
    end

    it 'succeeds with giving proc to count up' do
      n = 0
      allow_any_instance_of(Hoge).to receive(:hoge) { n += 1 }

      Hoge.new.hoge
      Hoge.new.hoge
      Hoge.new.hoge
      expect(n).to eq(3)
    end
  end

  module Foo
    def foo; end
  end

  class Bar
    include Foo
  end

  describe 'Bar' do
    it 'raise error with exactly matcher' do
      expect_any_instance_of(Bar).to receive(:foo).exactly(1).times

      Bar.new.foo
      expect { Bar.new.foo }.to raise_error(/The message 'foo' was received by #<Bar:.+ >/)
    end
    it 'succeeds with giving proc' do
      n = 0
      allow_any_instance_of(Foo).to receive(:foo) { n += 1 }

      Bar.new.foo
      Bar.new.foo
      Bar.new.foo
      expect(n).to eq(3)
    end
  end

end