1 files changed, 51 insertions, 0 deletions
diff --git a/activejob/test/cases/queue_adapter_test.rb b/activejob/test/cases/queue_adapter_test.rb
new file mode 100644
index 0000000000..e71cfa49cf
--- /dev/null
+++ b/activejob/test/cases/queue_adapter_test.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require "helper"
+
+module ActiveJob
+  module QueueAdapters
+    class StubOneAdapter
+      def enqueue(*); end
+      def enqueue_at(*); end
+    end
+
+    class StubTwoAdapter
+      def enqueue(*); end
+      def enqueue_at(*); end
+    end
+  end
+end
+
+class QueueAdapterTest < ActiveJob::TestCase
+  test "should forbid nonsense arguments" do
+    assert_raises(ArgumentError) { ActiveJob::Base.queue_adapter = Mutex }
+    assert_raises(ArgumentError) { ActiveJob::Base.queue_adapter = Mutex.new }
+  end
+
+  test "should allow overriding the queue_adapter at the child class level without affecting the parent or its sibling" do
+    ActiveJob::Base.disable_test_adapter
+    base_queue_adapter = ActiveJob::Base.queue_adapter
+
+    child_job_one = Class.new(ActiveJob::Base)
+    assert_equal child_job_one.queue_adapter_name, ActiveJob::Base.queue_adapter_name
+
+    child_job_one.queue_adapter = :stub_one
+
+    assert_not_equal ActiveJob::Base.queue_adapter, child_job_one.queue_adapter
+    assert_equal "stub_one", child_job_one.queue_adapter_name
+    assert_kind_of ActiveJob::QueueAdapters::StubOneAdapter, child_job_one.queue_adapter
+
+    child_job_two = Class.new(ActiveJob::Base)
+    child_job_two.queue_adapter = :stub_two
+
+    assert_equal "stub_two", child_job_two.queue_adapter_name
+
+    assert_kind_of ActiveJob::QueueAdapters::StubTwoAdapter, child_job_two.queue_adapter
+    assert_kind_of ActiveJob::QueueAdapters::StubOneAdapter, child_job_one.queue_adapter, "child_job_one's queue adapter should remain unchanged"
+    assert_equal base_queue_adapter, ActiveJob::Base.queue_adapter, "ActiveJob::Base's queue adapter should remain unchanged"
+
+    child_job_three = Class.new(ActiveJob::Base)
+
+    assert_not_nil child_job_three.queue_adapter
+  end
+end