Improve handling of weak etags with deflate (#2758)

ketan · ketan · commit 40999afb501a · 2016-10-05T07:56:13.000+05:30
diff --git a/server/webapp/WEB-INF/rails.new/lib/jetty_weak_etag_middleware.rb b/server/webapp/WEB-INF/rails.new/lib/jetty_weak_etag_middleware.rb
@@ -1,16 +1,35 @@
+##########################################################################
+# Copyright 2016 ThoughtWorks, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+##########################################################################
+
 class JettyWeakEtagMiddleware
   def initialize(app)
     @app = app
   end
 
+  MATCH_REGEX = /--(gzip|deflate)"$/
+  REPLACE_REGEX = /--(gzip|deflate)"?$/
+
   def call(env)
     # make weak etags sent by jetty strong see: http://stackoverflow.com/questions/18693718/weak-etags-in-rails
-    if env['HTTP_IF_MATCH'] =~ /--gzip"$/
-      env['HTTP_IF_MATCH'] = env['HTTP_IF_MATCH'].gsub(/--gzip"?$/, '"')
+    if env['HTTP_IF_MATCH'] =~ MATCH_REGEX
+      env['HTTP_IF_MATCH'] = env['HTTP_IF_MATCH'].gsub(REPLACE_REGEX, '"')
     end
 
-    if env['HTTP_IF_NONE_MATCH'] =~ /--gzip"$/
-      env['HTTP_IF_NONE_MATCH'] = env['HTTP_IF_NONE_MATCH'].gsub(/--gzip"?$/, '"')
+    if env['HTTP_IF_NONE_MATCH'] =~ MATCH_REGEX
+      env['HTTP_IF_NONE_MATCH'] = env['HTTP_IF_NONE_MATCH'].gsub(REPLACE_REGEX, '"')
     end
 
     status, headers, body = @app.call(env)
diff --git a/server/webapp/WEB-INF/rails.new/spec/lib/jetty_weak_etag_middleware_spec.rb b/server/webapp/WEB-INF/rails.new/spec/lib/jetty_weak_etag_middleware_spec.rb
@@ -0,0 +1,39 @@
+##########################################################################
+# Copyright 2016 ThoughtWorks, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+##########################################################################
+
+require 'spec_helper'
+
+describe JettyWeakEtagMiddleware do
+  before(:each) do
+    @app = double('rack-app')
+    @middleware = JettyWeakEtagMiddleware.new(@app)
+  end
+
+  %w(gzip deflate).each do |compression_type|
+    it "should remove --#{compression_type} suffix inserted by GzipFilter from jetty" do
+      env = {
+        'HTTP_IF_MATCH' => %Q{"foobar--#{compression_type}"},
+        'HTTP_IF_NONE_MATCH' => %Q{"foobar--#{compression_type}"}
+      }
+
+      @app.should_receive(:call).with({
+                                        'HTTP_IF_MATCH' => '"foobar"',
+                                        'HTTP_IF_NONE_MATCH' => '"foobar"'
+                                      })
+      @middleware.call(env)
+    end
+  end
+end
