Use I18n module for system messages instead of hard-coded value

lib/web_console.rb

@@ -3,6 +3,7 @@
 require 'active_support/lazy_load_hooks'
 require 'active_support/logger'
 
+require 'web_console/locale'
 require 'web_console/integration'
 require 'web_console/railtie'
 require 'web_console/errors'

lib/web_console/config/locales/en.yml

@@ -0,0 +1,15 @@
+en:
+  errors:
+    unavailable_session: |
+      Session %{id} is is no longer available in memory.
+
+      If you happen to run on a multi-process server (like Unicorn or Puma) the process
+      this request hit doesn't store %{id} in memory. Consider turning the number of
+      processes/workers to one (1) or using a different server in development.
+
+    unacceptable_request: |
+      A supported version is expected in the Accept header.
+
+    connection_refused: |
+      Oops! Failed to connect to the Web Console middleware.
+      Please make sure a rails development server is running.

lib/web_console/locale.rb

@@ -0,0 +1,2 @@
+require 'active_support/core_ext/string/access'
+I18n.load_path += Dir[ File.expand_path('../config/locales/*.yml', __FILE__) ]

lib/web_console/middleware.rb

@@ -4,16 +4,6 @@ module WebConsole
   class Middleware
     TEMPLATES_PATH = File.expand_path('../templates', __FILE__)
 
-    UNAVAILABLE_SESSION_MESSAGE = <<-END.strip_heredoc
-      Session %{id} is is no longer available in memory.
-
-      If you happen to run on a multi-process server (like Unicorn or Puma) the process
-      this request hit doesn't store %{id} in memory. Consider turning the number of
-      processes/workers to one (1) or using a different server in development.
-    END
-
-    UNACCEPTABLE_REQUEST_MESSAGE = "A supported version is expected in the Accept header."
-
     cattr_accessor :mount_point
     @@mount_point = '/__web_console'
 
@@ -115,13 +105,13 @@ def change_stack_trace(id, request)
 
       def respond_with_unavailable_session(id)
         json_response(status: 404) do
-          { output: format(UNAVAILABLE_SESSION_MESSAGE, id: id)}
+          { output: format(I18n.t('errors.unavailable_session'), id: id)}
         end
       end
 
       def respond_with_unacceptable_request
         json_response(status: 406) do
-          { error: UNACCEPTABLE_REQUEST_MESSAGE }
+          { output: I18n.t('errors.unacceptable_request') }
         end
       end
   end

lib/web_console/testing/fake_middleware.rb

@@ -4,6 +4,7 @@
 require 'web_console/whitelist'
 require 'web_console/request'
 require 'web_console/view'
+require 'web_console/locale'
 
 module WebConsole
   module Testing