bulk_change_table.rb in rubocop-rails-2.21.0

- old
+ new

@@ -10,11 +10,12 @@
       # ALTER TABLE statement combining multiple column alterations.
       #
       # The `bulk` option is only supported on the MySQL and
       # the PostgreSQL (5.2 later) adapter; thus it will
       # automatically detect an adapter from `development` environment
-      # in `config/database.yml` when the `Database` option is not set.
+      # in `config/database.yml` or the environment variable `DATABASE_URL`
+      # when the `Database` option is not set.
       # If the adapter is not `mysql2` or `postgresql`,
       # this Cop ignores offenses.
       #
       # @example
       #   # bad
@@ -173,24 +174,28 @@
 
           options.hash_type? && options.keys.any? { |key| key.sym_type? && key.value == :bulk }
         end
 
         def database
-          cop_config['Database'] || database_from_yaml
+          cop_config['Database'] || database_from_yaml || database_from_env
         end
 
         def database_from_yaml
           return nil unless database_yaml
 
-          case database_yaml['adapter']
+          case database_adapter
           when 'mysql2'
             MYSQL
           when 'postgresql'
             POSTGRESQL
           end
         end
 
+        def database_adapter
+          database_yaml['adapter'] || database_yaml.first.last['adapter']
+        end
+
         def database_yaml
           return nil unless File.exist?('config/database.yml')
 
           yaml = if YAML.respond_to?(:unsafe_load_file)
                    YAML.unsafe_load_file('config/database.yml')
@@ -203,9 +208,21 @@
           return nil unless config.is_a?(Hash)
 
           config
         rescue Psych::SyntaxError
           nil
+        end
+
+        def database_from_env
+          url = ENV['DATABASE_URL'].presence
+          return nil unless url
+
+          case url
+          when %r{\Amysql2://}
+            MYSQL
+          when %r{\Apostgres(ql)?://}
+            POSTGRESQL
+          end
         end
 
         def support_bulk_alter?
           case database
           when MYSQL