Add support for at and on_queue

deliver_later can be called with `wait`, `wait_until`, and `queue`
keyword arguments, so the have_enqueued_mail matcher should support
matching those types of things.  At this point, I am beginning to
suspect that this code would be better off using inheritance over
composition.  I am going to try and refactor to inherit from the
ActiveJob base matcher now that I have all of the tests in a good state.

Author: Joel Lubrano

lib/rspec/rails/matchers/have_enqueued_mail.rb

@@ -14,6 +14,8 @@ def initialize(mailer_class, method_name)
           @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)
         end
@@ -35,6 +37,18 @@ def with(*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
+
         %i[exactly at_least at_most].each do |method|
           define_method(method) do |count|
             @job_matcher.public_send(method, count)
@@ -73,8 +87,10 @@ def supports_block_expectations?
         def base_message
           "#{@mailer_class.name}.#{@method_name}".tap do |msg|
             msg << " #{expected_count_message}"
-            msg << " with #{@args}" if @args.any?
-            msg << ", but enqueued #{@job_matcher.matching_jobs.size}"
+            msg << " with #{@args}," if @args.any?
+            msg << " on queue #{@queue}," if @queue
+            msg << " at #{@at.inspect}," if @at
+            msg << " but enqueued #{@job_matcher.matching_jobs.size}"
           end
         end
 
@@ -125,19 +141,31 @@ def unmatching_mail_jobs_message
           msg = "Queued deliveries:"
 
           unmatching_mail_jobs.each do |job|
-            mailer_method = job[:args][0..1].join('.')
-            mailer_args = job[:args][3..-1]
-
-            msg << "\n  #{mailer_method}"
-            msg << " with #{mailer_args}" if mailer_args.any?
+            msg << "\n  #{mail_job_message(job)}"
           end
 
           msg
         end
+
+        def mail_job_message(job)
+          mailer_method = job[:args][0..1].join('.')
+
+          mailer_args = job[:args][3..-1]
+          msg_parts = []
+          msg_parts << "with #{mailer_args}" if mailer_args.any?
+          msg_parts << "on queue #{job[:queue]}" if job[:queue] && job[:queue] != 'mailers'
+          msg_parts << "at #{Time.at(job[:at])}" if job[:at]
+
+          "#{mailer_method} #{msg_parts.join(', ')}".strip
+        end
       end
 
       # @api public
-      # Passes if an email has been enqueued inside block. May chain with to specify expected arguments.
+      # Passes if an email has been enqueued inside block.
+      # May chain with to specify expected arguments.
+      # May chain at_least, at_most or exactly to specify a number of times.
+      # May chain at to specify a send time.
+      # May chain on_queue to specify a queue.
       #
       # @example
       #     expect {
@@ -152,6 +180,23 @@ def unmatching_mail_jobs_message
       #     expect {
       #       MyMailer.welcome(user).deliver_later
       #     }.to have_enqueued_mail(MyMailer, :welcome).with(user)
+      #
+      #     expect {
+      #       MyMailer.welcome(user).deliver_later
+      #       MyMailer.welcome(user).deliver_later
+      #     }.to have_enqueued_mail(MyMailer, :welcome).at_least(:once)
+      #
+      #     expect {
+      #       MyMailer.welcome(user).deliver_later
+      #     }.to have_enqueued_mail(MyMailer, :welcome).at_most(:twice)
+      #
+      #     expect {
+      #       MyMailer.welcome(user).deliver_later(wait_until: Date.tomorrow.noon)
+      #     }.to have_enqueued_mail(MyMailer, :welcome).at(Date.tomorrow.noon)
+      #
+      #     expect {
+      #       MyMailer.welcome(user).deliver_later(queue: :urgent_mail)
+      #     }.to have_enqueued_mail(MyMailer, :welcome).on_queue(:urgent_mail)
       def have_enqueued_mail(mailer_class, mail_method_name)
         check_active_job_adapter
         HaveEnqueuedMail.new(mailer_class, mail_method_name)

spec/rspec/rails/matchers/have_enqueued_mail_spec.rb

@@ -89,7 +89,7 @@ def email_with_optional_args(required_arg, optional_arg = nil); end
         expect {
           TestMailer.test_email.deliver_later
         }.not_to have_enqueued_mail(TestMailer, :test_email)
-      }.to raise_error(/expected not to enqueue TestMailer.test_email exactly 1 time, but enqueued 1/)
+      }.to raise_error(/expected not to enqueue TestMailer.test_email exactly 1 time but enqueued 1/)
     end
 
     it "passes with :once count" do
@@ -129,7 +129,7 @@ def email_with_optional_args(required_arg, optional_arg = nil); end
     it "generates a failure message with at least hint" do
       expect {
         expect { }.to have_enqueued_mail(TestMailer, :test_email).at_least(:once)
-      }.to raise_error(/expected to enqueue TestMailer.test_email at least 1 time, but enqueued 0/)
+      }.to raise_error(/expected to enqueue TestMailer.test_email at least 1 time but enqueued 0/)
     end
 
     it "generates a failure message with at most hint" do
@@ -138,7 +138,7 @@ def email_with_optional_args(required_arg, optional_arg = nil); end
           TestMailer.test_email.deliver_later
           TestMailer.test_email.deliver_later
         }.to have_enqueued_mail(TestMailer, :test_email).at_most(:once)
-      }.to raise_error(/expected to enqueue TestMailer.test_email at most 1 time, but enqueued 2/)
+      }.to raise_error(/expected to enqueue TestMailer.test_email at most 1 time but enqueued 2/)
     end
 
     it "passes for mailer methods that accept arguments when the provided argument matcher is not used" do
@@ -183,16 +183,47 @@ def email_with_optional_args(required_arg, optional_arg = nil); end
       }.to raise_error(/expected to enqueue TestMailer.email_with_args exactly 1 time with \[1, 2\], but enqueued 0/)
     end
 
+    it "passes when deliver_later is called with a wait_until argument" do
+      send_time = Date.tomorrow.noon
+
+      expect { TestMailer.test_email.deliver_later(wait_until: send_time) }
+        .to have_enqueued_email(TestMailer, :test_email).at(send_time)
+    end
+
+    it "generates a failure message with at" do
+      send_time = Date.tomorrow.noon
+
+      expect {
+        expect { TestMailer.test_email.deliver_later(wait_until: send_time + 1) }
+          .to have_enqueued_email(TestMailer, :test_email).at(send_time)
+      }.to raise_error(/expected to enqueue TestMailer.test_email exactly 1 time at #{send_time.inspect}/)
+    end
+
+    it "passes when deliver_later is called with a queue argument" do
+      expect { TestMailer.test_email.deliver_later(queue: 'urgent_mail') }
+        .to have_enqueued_email(TestMailer, :test_email).on_queue('urgent_mail')
+    end
+
+    it "generates a failure message with on_queue" do
+      expect {
+        expect { TestMailer.test_email.deliver_later(queue: 'not_urgent_mail') }
+          .to have_enqueued_email(TestMailer, :test_email).on_queue('urgent_mail')
+      }.to raise_error(/expected to enqueue TestMailer.test_email exactly 1 time on queue urgent_mail/)
+    end
+
     it "generates a failure message with unmatching enqueued mail jobs" do
+      send_time = Date.tomorrow.noon
+      queue = 'urgent_mail'
+
       message = "expected to enqueue TestMailer.email_with_args exactly 1 time with [1, 2], but enqueued 0" + \
                 "\nQueued deliveries:" + \
                 "\n  TestMailer.test_email" + \
-                "\n  TestMailer.email_with_args with [3, 4]"
+                "\n  TestMailer.email_with_args with [3, 4], on queue #{queue}, at #{send_time}"
 
       expect {
         expect {
           TestMailer.test_email.deliver_later
-          TestMailer.email_with_args(3, 4).deliver_later
+          TestMailer.email_with_args(3, 4).deliver_later(wait_until: send_time, queue: queue)
         }.to have_enqueued_email(TestMailer, :email_with_args).with(1, 2)
       }.to raise_error(message)
     end