Rails migrations should specify the version

  class CreateDelayedJobs < ActiveRecord::Migration[4.2]

rather than

  class CreateDelayedJobs < ActiveRecord::Migration

Author: matthewrudy

lib/generators/delayed_job/active_record_generator.rb

@@ -12,11 +12,19 @@ class ActiveRecordGenerator < ::DelayedJobGenerator
     source_paths << File.join(File.dirname(__FILE__), "templates")
 
     def create_migration_file
-      migration_template "migration.rb", "db/migrate/create_delayed_jobs.rb"
+      migration_template "migration.rb", "db/migrate/create_delayed_jobs.rb", migration_version: migration_version
     end
 
     def self.next_migration_number(dirname)
       ActiveRecord::Generators::Base.next_migration_number dirname
     end
+
+    private
+
+    def migration_version
+      if ActiveRecord::VERSION::MAJOR >= 5
+        "[#{ActiveRecord::VERSION::MAJOR}.#{ActiveRecord::VERSION::MINOR}]"
+      end
+    end
   end
 end

lib/generators/delayed_job/templates/migration.rb

@@ -1,4 +1,4 @@
-class CreateDelayedJobs < ActiveRecord::Migration
+class CreateDelayedJobs < ActiveRecord::Migration<%= migration_version %>
   def self.up
     create_table :delayed_jobs, force: true do |table|
       table.integer :priority, default: 0, null: false # Allows some jobs to jump to the front of the queue

lib/generators/delayed_job/templates/upgrade_migration.rb

@@ -1,4 +1,4 @@
-class AddQueueToDelayedJobs < ActiveRecord::Migration
+class AddQueueToDelayedJobs < ActiveRecord::Migration<%= migration_version %>
   def self.up
     add_column :delayed_jobs, :queue, :string
   end

lib/generators/delayed_job/upgrade_generator.rb

@@ -5,18 +5,9 @@
 
 # Extend the DelayedJobGenerator so that it creates an AR migration
 module DelayedJob
-  class UpgradeGenerator < ::DelayedJobGenerator
-    include Rails::Generators::Migration
-    extend NextMigrationVersion
-
-    source_paths << File.join(File.dirname(__FILE__), "templates")
-
+  class UpgradeGenerator < ActiveRecordGenerator
     def create_migration_file
-      migration_template "upgrade_migration.rb", "db/migrate/add_queue_to_delayed_jobs.rb"
-    end
-
-    def self.next_migration_number(dirname)
-      ActiveRecord::Generators::Base.next_migration_number dirname
+      migration_template "upgrade_migration.rb", "db/migrate/add_queue_to_delayed_jobs.rb", migration_version: migration_version
     end
   end
 end

spec/helper.rb

@@ -33,7 +33,26 @@
 ActiveRecord::Base.logger = Delayed::Worker.logger
 ActiveRecord::Migration.verbose = false
 
-require "generators/delayed_job/templates/migration"
+migration_template = File.open("lib/generators/delayed_job/templates/migration.rb")
+
+# need to eval the template with the migration_version intact
+migration_context = Class.new do
+  def get_binding
+    binding
+  end
+
+  private
+
+  def migration_version
+    if ActiveRecord::VERSION::MAJOR >= 5
+      "[#{ActiveRecord::VERSION::MAJOR}.#{ActiveRecord::VERSION::MINOR}]"
+    end
+  end
+end
+
+migration_ruby = ERB.new(migration_template.read).result(migration_context.new.get_binding)
+eval(migration_ruby)
+
 ActiveRecord::Schema.define do
   CreateDelayedJobs.up