decide when run rake or rails routes.

README.md

@@ -49,7 +49,7 @@ when using `SpatialAdapter`, `PostgisAdapter` or `PostGISAdapter`:
 #  path            :geometry        line_string, 4326
 ```
 
-Also, if you pass the `-r` option, it'll annotate `routes.rb` with the output of `rake routes`.
+Also, if you pass the `-r` option, it'll annotate `routes.rb` with the output of `rake/rails routes`.
 
 
 ## Upgrading to 3.X and annotate models not working?
@@ -217,7 +217,7 @@ you can do so with a simple environment variable, instead of editing the
                                          If --w option is used, the same text will be used as opening and closing
             --wo, --wrapper-open STR     Annotation wrapper opening.
             --wc, --wrapper-close STR    Annotation wrapper closing
-        -r, --routes                     Annotate routes.rb with the output of 'rake routes'
+        -r, --routes                     Annotate routes.rb with the output of 'rake/rails routes'
             --models                     Annotate ActiveRecord models
         -a, --active-admin               Annotate active_admin models
         -v, --version                    Show the current version of this gem

lib/annotate/annotate_routes.rb

@@ -4,7 +4,7 @@
 #
 #
 #
-# Prepends the output of "rake routes" to the top of your routes.rb file.
+# Prepends the output of "rake/rails routes" to the top of your routes.rb file.
 # Yes, it's simple but I'm thick and often need a reminder of what my routes
 # mean.
 #

lib/annotate/annotate_routes/header_generator.rb

@@ -16,7 +16,8 @@ def generate(options = {})
       private
 
       def routes_map(options)
-        result = `rake routes`.chomp("\n").split(/\n/, -1)
+        command = Rails.version.first.to_i > 5 ? `rails routes` : `rake routes`
+        result = command.chomp("\n").split(/\n/, -1)
 
         # In old versions of Rake, the first line of output was the cwd.  Not so
         # much in newer ones.  We ditch that line if it exists, and if not, we

lib/annotate/parser.rb

@@ -145,7 +145,7 @@ def add_options_to_parser(option_parser) # rubocop:disable Metrics/MethodLength,
 
       option_parser.on('-r',
                        '--routes',
-                       "Annotate routes.rb with the output of 'rake routes'") do
+                       "Annotate routes.rb with the output of 'rake/rails routes'") do
         env['routes'] = 'true'
       end