lib/eeny-meeny/middleware.rb in eeny-meeny-2.1.4 vs lib/eeny-meeny/middleware.rb in eeny-meeny-2.2.0

@@ -22,48 +22,75 @@
     def call(env)
       cookies          = Rack::Utils.parse_query(env[HTTP_COOKIE],';,')  { |s| Rack::Utils.unescape(s) rescue s }
       query_parameters = query_hash(env)
       now              = Time.zone.now
       new_cookies      = {}
+      delete_cookies   = find_deprecated_cookies(cookies, now)
       # Prepare for experiments.
       @experiments.each do |experiment|
         # Skip inactive experiments
         next unless experiment.active?(now)
-        # Trigger experiment through query parameters
-        cookie_name = EenyMeeny::Cookie.cookie_name(experiment)
-        has_experiment_trigger = EenyMeeny.config.query_parameters[:experiment] && query_parameters.key?(cookie_name)
-        # skip experiments that already have a cookie
-        next unless has_experiment_trigger || !cookies.key?(cookie_name)
-        cookie = if has_experiment_trigger
-                   # Trigger experiment variation through query parameter.
-                   EenyMeeny::Cookie.create_for_experiment_variation(experiment, query_parameters[cookie_name].to_sym, @cookie_config)
-                 else
-                   EenyMeeny::Cookie.create_for_experiment(experiment, @cookie_config)
-                 end
-        # Set HTTP_COOKIE header to enable experiment on first pageview
-        env = add_or_replace_http_cookie(env, cookie)
-        new_cookies[cookie.name] = cookie
+        env, new_cookies = prepare_experiment(env, cookies, new_cookies, query_parameters, experiment)
       end
-      # Prepare smoke tests (if enabled through query parameters)
-      if EenyMeeny.config.query_parameters[:smoke_test]
-        if query_parameters.key?('smoke_test_id') && (query_parameters['smoke_test_id'] =~ /\A[A-Za-z_]+\z/)
-          # Set HTTP_COOKIE header to enable smoke test on first pageview
-          cookie = EenyMeeny::Cookie.create_for_smoke_test(query_parameters['smoke_test_id'], @cookie_config)
-          env = add_or_replace_http_cookie(env, cookie)
-          new_cookies[cookie.name] = cookie
-        end
-      end
+      # Prepare smoke tests
+      env, new_cookies = prepare_smoke_test(env, new_cookies, query_parameters)
       # Delegate to app
       status, headers, body = @app.call(env)
       response = Rack::Response.new(body, status, headers)
       # Add new cookies to 'Set-Cookie' header
       new_cookies.each do |key, value|
         response.set_cookie(key,value.to_h)
       end
+      delete_cookies.each do |key, value|
+        response.delete_cookie(key, value: value, path: @cookie_config[:path], same_site: @cookie_config[:same_site])
+      end
       response.finish
     end
 
     private
+
+    def find_deprecated_cookies(cookies, now)
+      deprecated_cookies = {}
+      cookies.each do |cookie_name, value|
+        # Skip any cookie that does not have the 'eeny_meeny_' prefix
+        next unless cookie_name.to_s.start_with?(EenyMeeny::Cookie::EXPERIMENT_PREFIX)
+        # Mark cookies that does not match any existing active experiment as 'deprecated'.
+        experiment = EenyMeeny::Experiment.find_by_cookie_name(cookie_name)
+        next if experiment && experiment.active?(now)
+        deprecated_cookies[cookie_name] = value
+      end
+      deprecated_cookies
+    end
+
+    def prepare_experiment(env, cookies, new_cookies, query_parameters, experiment)
+      # Trigger experiment through query parameters
+      cookie_name = EenyMeeny::Cookie.cookie_name(experiment)
+      has_experiment_trigger = EenyMeeny.config.query_parameters[:experiment] && query_parameters.key?(cookie_name)
+      # Skip experiments that already have a cookie
+      return env, new_cookies unless has_experiment_trigger || !cookies.key?(cookie_name)
+      cookie = if has_experiment_trigger
+                 # Trigger experiment variation through query parameter.
+                 EenyMeeny::Cookie.create_for_experiment_variation(experiment, query_parameters[cookie_name].to_sym, @cookie_config)
+               else
+                 EenyMeeny::Cookie.create_for_experiment(experiment, @cookie_config)
+               end
+      # Set HTTP_COOKIE header to enable experiment on first pageview
+      env = add_or_replace_http_cookie(env, cookie)
+      new_cookies[cookie.name] = cookie
+      return env, new_cookies
+    end
+
+    def prepare_smoke_test(env, new_cookies, query_parameters)
+      # Skip if the EenyMeeny 'smoke test' query parameters configuration is disabled.
+      return env, new_cookies unless EenyMeeny.config.query_parameters[:smoke_test]
+      # Skip if no valid 'smoke_test_id' query parameter present
+      return env, new_cookies unless query_parameters.key?('smoke_test_id') && (query_parameters['smoke_test_id'] =~ /\A[A-Za-z_]+\z/)
+      # Set HTTP_COOKIE header to enable smoke test on first pageview
+      cookie = EenyMeeny::Cookie.create_for_smoke_test(query_parameters['smoke_test_id'], @cookie_config)
+      env = add_or_replace_http_cookie(env, cookie)
+      new_cookies[cookie.name] = cookie
+      return env, new_cookies
+    end
 
     def query_hash(env)
       # Query Params are only relevant if EenyMeeny.config have them enabled.
       return {} unless EenyMeeny.config.query_parameters[:experiment] || EenyMeeny.config.query_parameters[:smoke_test]
       # Query Params are only relevant to HTTP GET requests.