Ensure test jobs are marshallable

By marshalling and unmarshalling jobs when adding them to the test queue, we
can ensure that jobs created during test runs are valid candidates for
marshalling, and, thus, that they can be used with queueing backends other than
the default simple in-process implementation.

This will also be used in a subsequent commit to ensure that jobs pushed to the
queue do not contain a reference to the queue itself.

1 files changed, 28 insertions, 8 deletions

diff --git a/railties/test/application/queue_test.rb b/railties/test/application/queue_test.rb
index d5198b07e8..e8ee8c5c9f 100644
--- a/railties/test/application/queue_test.rb
+++ b/railties/test/application/queue_test.rb
@@ -62,24 +62,36 @@ module ApplicationTests
     test "in test mode, explicitly draining the queue will process it in a separate thread" do
       app("test")
 
-      job = ThreadTrackingJob.new
-      Rails.queue.push job
+      Rails.queue.push ThreadTrackingJob.new
+      job = Rails.queue.jobs.last
       Rails.queue.drain
 
       assert job.ran?, "Expected job to be run"
       assert job.ran_in_different_thread?, "Expected job to run in a different thread"
     end
 
-    test "in test mode, the queue can be observed" do
-      app("test")
+    class IdentifiableJob
+      def initialize(id)
+        @id = id
+      end
 
-      job = Struct.new(:id) do
-        def run
-        end
+      def ==(other)
+        other.same_id?(@id)
+      end
+
+      def same_id?(other_id)
+        other_id == @id
+      end
+
+      def run
       end
+    end
+
+    test "in test mode, the queue can be observed" do
+      app("test")
 
       jobs = (1..10).map do |id|
-        job.new(id)
+        IdentifiableJob.new(id)
       end
 
       jobs.each do |job|
@@ -89,6 +101,14 @@ module ApplicationTests
       assert_equal jobs, Rails.queue.jobs
     end
 
+    test "in test mode, adding an unmarshallable job will raise an exception" do
+      app("test")
+      anonymous_class_instance = Struct.new(:run).new
+      assert_raises TypeError do
+        Rails.queue.push anonymous_class_instance
+      end
+    end
+
     def setup_custom_queue
       add_to_env_config "production", <<-RUBY
         require "my_queue"