Make digest cache work in development.

Avoid computing the same fragment digest many times when looping over templates.

The cache is cleared on every request so template changes are still picked up.

1 files changed, 63 insertions, 0 deletions

diff --git a/railties/test/application/per_request_digest_cache_test.rb b/railties/test/application/per_request_digest_cache_test.rb
new file mode 100644
index 0000000000..3198e12662
--- /dev/null
+++ b/railties/test/application/per_request_digest_cache_test.rb
@@ -0,0 +1,63 @@
+require 'isolation/abstract_unit'
+require 'rack/test'
+require 'minitest/mock'
+
+require 'action_view'
+require 'active_support/testing/method_call_assertions'
+
+class PerRequestDigestCacheTest < ActiveSupport::TestCase
+  include ActiveSupport::Testing::Isolation
+  include ActiveSupport::Testing::MethodCallAssertions
+  include Rack::Test::Methods
+
+  setup do
+    build_app
+    add_to_config 'config.consider_all_requests_local = true'
+
+    app_file 'app/models/customer.rb', <<-RUBY
+      class Customer < Struct.new(:name, :id)
+        extend ActiveModel::Naming
+        include ActiveModel::Conversion
+      end
+    RUBY
+
+    app_file 'config/routes.rb', <<-RUBY
+      Rails.application.routes.draw do
+        resources :customers, only: :index
+      end
+    RUBY
+
+    app_file 'app/controllers/customers_controller.rb', <<-RUBY
+      class CustomersController < ApplicationController
+        def index
+          render [ Customer.new('david', 1), Customer.new('dingus', 2) ]
+        end
+      end
+    RUBY
+
+    app_file 'app/views/customers/_customer.html.erb', <<-RUBY
+      <% cache customer do %>
+        <%= customer.name %>
+      <% end %>
+    RUBY
+
+    require "#{app_path}/config/environment"
+  end
+
+  teardown :teardown_app
+
+  test "digests are reused when rendering the same template twice" do
+    get '/customers'
+    assert_equal 200, last_response.status
+
+    assert_equal [ '8ba099b7749542fe765ff34a6824d548' ], ActionView::Digestor.cache.values
+    assert_equal %w(david dingus), last_response.body.split.map(&:strip)
+  end
+
+  test "template digests are cleared before a request" do
+    assert_called(ActionView::Digestor.cache, :clear) do
+      get '/customers'
+      assert_equal 200, last_response.status
+    end
+  end
+end