Fix parameter matching with mail delivery job and ActionMailer::MailDeliveryJob

features/matchers/have_enqueued_mail_matcher.feature

@@ -38,3 +38,40 @@ Feature: have_enqueued_mail matcher
       """
     When I run `rspec spec/mailers/user_mailer_spec.rb`
     Then the examples should all pass
+
+  Scenario: Checking mailer arguments
+    Given a file named "app/mailers/my_mailer.rb" with:
+      """ruby
+      class MyMailer < ApplicationMailer
+
+        def signup(user = nil)
+          @user = user
+
+          mail to: "[email protected]"
+        end
+      end
+      """
+    Given a file named "spec/mailers/my_mailer_spec.rb" with:
+      """ruby
+      require "rails_helper"
+
+      RSpec.describe MyMailer do
+        it "matches with enqueued mailer" do
+          ActiveJob::Base.queue_adapter = :test
+          # Works with plain args
+          expect {
+            MyMailer.signup('user').deliver_later
+          }.to have_enqueued_mail(MyMailer, :signup).with('user')
+          # Works with named parameters
+          expect {
+            MyMailer.with('foo' => 'bar').signup.deliver_later
+          }.to have_enqueued_mail(MyMailer, :signup).with('foo' => 'bar')
+          # Works also with both, named parameters match first argument
+          expect {
+            MyMailer.with('foo' => 'bar').signup('user').deliver_later
+          }.to have_enqueued_mail(MyMailer, :signup).with({'foo' => 'bar'}, 'user')
+        end
+      end
+      """
+    When I run `rspec spec/mailers/my_mailer_spec.rb`
+    Then the examples should all pass

lib/rspec/rails/matchers/have_enqueued_mail.rb

@@ -76,7 +76,7 @@ def job_match?(job)
         def arguments_match?(job)
           @args =
             if @mail_args.any?
-              base_mailer_args + @mail_args
+              base_mailer_args + process_arguments(job, @mail_args)
             elsif @mailer_class && @method_name
               base_mailer_args + [any_args]
             elsif @mailer_class
@@ -88,6 +88,18 @@ def arguments_match?(job)
           super(job)
         end
 
+        def process_arguments(job, given_mail_args)
+          if job[:job] == ActionMailer::MailDeliveryJob
+            if given_mail_args.first.is_a?(Hash) && job[:args][3]['params'].present?
+              [hash_including(params: given_mail_args[0], args: given_mail_args.drop(1))]
+            else
+              [hash_including(args: given_mail_args)]
+            end
+          else
+            given_mail_args
+          end
+        end
+
         def base_mailer_args
           [mailer_class_name, @method_name.to_s, MAILER_JOB_METHOD]
         end
@@ -120,7 +132,6 @@ def unmatching_mail_jobs_message
 
         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?

spec/rspec/rails/matchers/have_enqueued_mail_spec.rb

@@ -393,18 +393,22 @@ def self.name; "NonMailerJob"; end
         }.to have_enqueued_mail(UnifiedMailer, :test_email).and have_enqueued_mail(UnifiedMailer, :email_with_args)
       end
 
-      it "passes with provided argument matchers" do
+      it "matches arguments when mailer has only args" do
+        expect {
+          UnifiedMailer.email_with_args(1, 2).deliver_later
+        }.to have_enqueued_mail(UnifiedMailer, :email_with_args).with(1, 2)
+      end
+
+      it "matches arguments when mailer is parameterized" do
         expect {
           UnifiedMailer.with('foo' => 'bar').test_email.deliver_later
-        }.to have_enqueued_mail(UnifiedMailer, :test_email).with(
-          a_hash_including(params: {'foo' => 'bar'})
-        )
+        }.to have_enqueued_mail(UnifiedMailer, :test_email).with('foo' => 'bar')
+      end
 
+      it "matches arguments when mixing parameterized and non-parameterized emails" do
         expect {
           UnifiedMailer.with('foo' => 'bar').email_with_args(1, 2).deliver_later
-        }.to have_enqueued_mail(UnifiedMailer, :email_with_args).with(
-          a_hash_including(params: {'foo' => 'bar'}, args: [1, 2])
-        )
+        }.to have_enqueued_mail(UnifiedMailer, :email_with_args).with({'foo' => 'bar'}, 1, 2)
       end
 
       it "passes when using a mailer with `delivery_job` set to a sub class of `ActionMailer::DeliveryJob`" do