1 files changed, 62 insertions, 0 deletions
diff --git a/actionpack/test/controller/new_base/render_partial_test.rb b/actionpack/test/controller/new_base/render_partial_test.rb
new file mode 100644
index 0000000000..a0c7cbc686
--- /dev/null
+++ b/actionpack/test/controller/new_base/render_partial_test.rb
@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+require "abstract_unit"
+
+module RenderPartial
+  class BasicController < ActionController::Base
+    self.view_paths = [ActionView::FixtureResolver.new(
+      "render_partial/basic/_basic.html.erb"      => "BasicPartial!",
+      "render_partial/basic/basic.html.erb"       => "<%= @test_unchanged = 'goodbye' %><%= render :partial => 'basic' %><%= @test_unchanged %>",
+      "render_partial/basic/with_json.html.erb"   => "<%= render :partial => 'with_json', :formats => [:json] %>",
+      "render_partial/basic/_with_json.json.erb"  => "<%= render :partial => 'final', :formats => [:json] %>",
+      "render_partial/basic/_final.json.erb"      => "{ final: json }",
+      "render_partial/basic/overridden.html.erb"  => "<%= @test_unchanged = 'goodbye' %><%= render :partial => 'overridden' %><%= @test_unchanged %>",
+      "render_partial/basic/_overridden.html.erb" => "ParentPartial!",
+      "render_partial/child/_overridden.html.erb" => "OverriddenPartial!"
+    )]
+
+    def html_with_json_inside_json
+      render action: "with_json"
+    end
+
+    def changing
+      @test_unchanged = "hello"
+      render action: "basic"
+    end
+
+    def overridden
+      @test_unchanged = "hello"
+    end
+  end
+
+  class ChildController < BasicController; end
+
+  class TestPartial < Rack::TestCase
+    testing BasicController
+
+    test "rendering a partial in ActionView doesn't pull the ivars again from the controller" do
+      get :changing
+      assert_response("goodbyeBasicPartial!goodbye")
+    end
+
+    test "rendering a template with renders another partial with other format that renders other partial in the same format" do
+      get :html_with_json_inside_json
+      assert_content_type "text/html; charset=utf-8"
+      assert_response "{ final: json }"
+    end
+  end
+
+  class TestInheritedPartial < Rack::TestCase
+    testing ChildController
+
+    test "partial from parent controller gets picked if missing in child one" do
+      get :changing
+      assert_response("goodbyeBasicPartial!goodbye")
+    end
+
+    test "partial from child controller gets picked" do
+      get :overridden
+      assert_response("goodbyeOverriddenPartial!goodbye")
+    end
+  end
+end