Refactor HaveEnqueuedMail matcher to be a subclass of the HaveEnqueuedJob matcher

Implementing as a subclass resulted in DRYer code IMO.  There was no
longer a need to reimplement once, twice, thrice and other duplicated
methods that were basically just delegating to the job_matcher instance
variable anyways.

Author: Joel Lubrano

lib/rspec/rails/matchers/active_job.rb

@@ -11,8 +11,6 @@ module ActiveJob
         # rubocop: disable Style/ClassLength
         # @private
         class Base < RSpec::Matchers::BuiltIn::BaseMatcher
-          attr_reader :matching_jobs, :unmatching_jobs
-
           def initialize
             @args = []
             @queue = nil

lib/rspec/rails/matchers/have_enqueued_mail.rb

@@ -9,65 +9,30 @@ module Matchers
       # rubocop: disable Style/ClassLength
       # @private
       # @see RSpec::Rails::Matchers#have_enqueued_mail
-      class HaveEnqueuedMail < RSpec::Matchers::BuiltIn::BaseMatcher
+      class HaveEnqueuedMail < ActiveJob::HaveEnqueuedJob
         include RSpec::Mocks::ExampleMethods
 
         def initialize(mailer_class, method_name)
+          super(mailer_job)
           @mailer_class = mailer_class
           @method_name = method_name
-          @args = []
-          @at = nil
-          @queue = nil
-          @job_matcher = ActiveJob::HaveEnqueuedJob.new(ActionMailer::DeliveryJob)
-          set_expected_count(:exactly, 1)
+          @mail_args = []
+          @args = mailer_args
         end
 
         def description
           "enqueues #{@mailer_class.name}.#{@method_name}"
         end
 
-        def matches?(block)
-          raise ArgumentError, 'have_enqueued_mail and enqueue_mail only work with block arguments' unless block.respond_to?(:call)
-          check_active_job_adapter
-
-          @job_matcher.with(*mailer_args)
-          @job_matcher.matches?(block)
-        end
-
         def with(*args)
-          @args = args
-          self
-        end
-
-        def at(send_time)
-          @at = send_time
-          @job_matcher.at(send_time)
-          self
-        end
-
-        def on_queue(queue)
-          @queue = queue
-          @job_matcher.on_queue(queue)
-          self
-        end
-
-        [:exactly, :at_least, :at_most].each do |method|
-          define_method(method) do |count|
-            @job_matcher.public_send(method, count)
-            set_expected_count(method, count)
-            self
-          end
+          @mail_args = args
+          super(*mailer_args)
         end
 
-        [:once, :twice, :thrice].each do |method|
-          define_method(method) do
-            @job_matcher.public_send(method)
-            exactly(method)
-          end
-        end
-
-        def times
-          self
+        def matches?(block)
+          raise ArgumentError, 'have_enqueued_mail and enqueue_mail only work with block arguments' unless block.respond_to?(:call)
+          check_active_job_adapter
+          super
         end
 
         def failure_message
@@ -80,31 +45,27 @@ def failure_message_when_negated
           "expected not to enqueue #{base_message}"
         end
 
-        def supports_block_expectations?
-          true
-        end
-
         private
 
         def base_message
           "#{@mailer_class.name}.#{@method_name}".tap do |msg|
             msg << " #{expected_count_message}"
-            msg << " with #{@args}," if @args.any?
+            msg << " with #{@mail_args}," if @mail_args.any?
             msg << " on queue #{@queue}," if @queue
             msg << " at #{@at.inspect}," if @at
-            msg << " but enqueued #{@job_matcher.matching_jobs.size}"
+            msg << " but enqueued #{@matching_jobs.size}"
           end
         end
 
         def expected_count_message
-          "#{@expected_count_type.to_s.tr('_', ' ')} #{@expected_count} #{@expected_count == 1 ? 'time' : 'times'}"
+          "#{message_expectation_modifier} #{@expected_number} #{@expected_number == 1 ? 'time' : 'times'}"
         end
 
         def mailer_args
           base_args = [@mailer_class.name, @method_name.to_s, 'deliver_now']
 
-          if @args.any?
-            base_args + @args
+          if @mail_args.any?
+            base_args + @mail_args
           else
             mailer_method_arity = @mailer_class.instance_method(@method_name).arity
 
@@ -123,19 +84,9 @@ def check_active_job_adapter
           raise StandardError, "To use HaveEnqueuedMail matcher set `ActiveJob::Base.queue_adapter = :test`"
         end
 
-        def set_expected_count(relativity, count)
-          @expected_count_type = relativity
-          @expected_count = case count
-                            when :once then 1
-                            when :twice then 2
-                            when :thrice then 3
-                            else Integer(count)
-                            end
-        end
-
         def unmatching_mail_jobs
-          @job_matcher.unmatching_jobs.select do |job|
-            job[:job] == ActionMailer::DeliveryJob
+          @unmatching_jobs.select do |job|
+            job[:job] == mailer_job
           end
         end
 
@@ -160,6 +111,10 @@ def mail_job_message(job)
 
           "#{mailer_method} #{msg_parts.join(', ')}".strip
         end
+
+        def mailer_job
+          ActionMailer::DeliveryJob
+        end
       end
       # rubocop: enable Style/ClassLength