Adding config block and transaction adapter configuration

.reek

@@ -1,7 +1,8 @@
 ---
 Attribute:
   enabled: true
-  exclude: []
+  exclude:
+  - Que::Scheduler
 BooleanParameter:
   enabled: false
   exclude: []

CHANGELOG.md

@@ -1,5 +1,7 @@
-## Unreleased
+## 3.1.0 (2018-06-01)
 
+* Addition of a gem config initializer [#29](https://github.com/hlascelles/que-scheduler/pull/29)
+* Allow configuration of the transaction block adapter [#29](https://github.com/hlascelles/que-scheduler/pull/29)
 * Handling middle overriding enqueue that prevents a job from being enqueued [#28](https://github.com/hlascelles/que-scheduler/pull/28)
 
 ## 3.0.0 (2018-05-23)

README.md

@@ -18,8 +18,8 @@ needs to be run, enqueueing those jobs, then enqueueing itself to check again la
     ```ruby
     gem 'que-scheduler'
     ```
-1. Specify a schedule config in a yml file (see below). The default location that que-scheduler will 
-look for it is `config/que_schedule.yml`. They are essentially the same as resque-scheduler config
+1. Specify a schedule in a yml file (see below). The default location that que-scheduler will 
+look for it is `config/que_schedule.yml`. They are essentially the same as resque-scheduler
 files, but with additional features.
 
 1. Add a migration to start the job scheduler and prepare the audit table.
@@ -35,7 +35,7 @@ files, but with additional features.
 ## Schedule configuration
 
 The schedule file is a list of que job classes with arguments and a schedule frequency (in crontab 
-syntax). The format is similar to the resque-scheduler config format, though priorities must be supplied as
+syntax). The format is similar to the resque-scheduler format, though priorities must be supplied as
 integers, and job classes must be migrated from Resque to Que. Cron syntax can be anything
 understood by [fugit](https://github.com/floraison/fugit#fugitcron).
 
@@ -111,11 +111,22 @@ A job can have a `schedule_type` assigned to it. Valid values are:
    This feature ensures that jobs which *must run* for a certain cron match will always eventually 
   execute, even after a total system crash, or even a DB backup restore.
 
-## Environment Variables
+## Gem configuration
 
-You can configure some aspects of the gem with environment variables.
+You can configure some aspects of the gem with an initializer. The default is given below.
 
-* `QUE_SCHEDULER_CONFIG_LOCATION` - The location of the schedule configuration (default `config/que_schedule.yml`)
+```ruby
+Que::Scheduler.configure do |config|
+  # The location of the schedule yaml file.
+  config.schedule_location = ENV.fetch('QUE_SCHEDULER_CONFIG_LOCATION', 'config/que_schedule.yml')
+  
+  # Specify a transaction block adapter. By default, que-scheduler uses the one supplied by que.
+  # However, if, for example you rely on listeners to ActiveRecord's exact `transaction` method, or 
+  # Sequel's DB.after_commit helper, then you can supply it here.
+  config.transaction_adapter = ::Que.method(:transaction)
+end
+
+```
 
 ## Scheduler Audit
 
@@ -134,7 +145,7 @@ in a coherent state with the rest of your database.
 
 ## Concurrent scheduler detection
 
-No matter how many tasks you have defined in your config, you will only ever need one que-scheduler
+No matter how many tasks you have defined in your schedule, you will only ever need one que-scheduler
 job enqueued. que-scheduler knows this, and it will check before performing any operations that 
 there is only one of itself present.
 
@@ -144,15 +155,15 @@ it will rollback correctly and try again. It won't schedule jobs twice for a cro
 
 ## How it works
 
-que-scheduler is a job that reads a config file, enqueues any jobs it determines that need to be run,
+que-scheduler is a job that reads a schedule file, enqueues any jobs it determines that need to be run,
 then reschedules itself. The flow is as follows:
 
 1. The que-scheduler job runs for the very first time.
-1. que-scheduler loads the schedule config file. It will not schedule any other jobs, except itself, 
+1. que-scheduler loads the schedule file. It will not schedule any other jobs, except itself, 
    as it has never run before.
 1. Some time later it runs again. It knows what jobs it should be monitoring, and notices that some 
    have are due. It enqueues those jobs and then itself. Repeat.
-1. After a deploy that changes the config, the job notices any new jobs to schedule, and knows which
+1. After a deploy that changes the schedule, the job notices any new jobs to schedule, and knows which
    ones to forget. It does not need to be re-enqueued or restarted.
    
 ## DB Migrations
@@ -182,6 +193,7 @@ Major feature changes are listed below. The full
 the root of the project. 
 
 #### Versions 3.x 
+  - Addition of a config initializer.
   - Addition of numerous extra columns to the audit table.
   - Required cumulative migration: `Que::Scheduler::Migrations.migrate!(version: 4)`
 #### Versions 2.x 

lib/que-scheduler.rb

@@ -0,0 +1,3 @@
+# rubocop:disable Naming/FileName
+require 'que/scheduler'
+# rubocop:enable Naming/FileName

lib/que/scheduler.rb

@@ -1,4 +1,5 @@
 require 'que/scheduler/version'
+require 'que/scheduler/config'
 require 'que/scheduler/scheduler_job'
 require 'que/scheduler/db'
 require 'que/scheduler/audit'

lib/que/scheduler/config.rb

@@ -0,0 +1,24 @@
+require 'que'
+
+module Que
+  module Scheduler
+    class << self
+      attr_accessor :configuration
+    end
+
+    def self.configure
+      self.configuration ||= Configuration.new
+      yield(configuration)
+    end
+
+    class Configuration
+      attr_accessor :schedule_location
+      attr_accessor :transaction_adapter
+    end
+  end
+end
+
+Que::Scheduler.configure do |config|
+  config.schedule_location = ENV.fetch('QUE_SCHEDULER_CONFIG_LOCATION', 'config/que_schedule.yml')
+  config.transaction_adapter = ::Que.method(:transaction)
+end

lib/que/scheduler/db.rb

@@ -15,6 +15,10 @@ def count_schedulers
         def now
           Que.execute(NOW_SQL).first.values.first
         end
+
+        def transaction
+          Que::Scheduler.configuration.transaction_adapter.call { yield }
+        end
       end
     end
   end

lib/que/scheduler/defined_job.rb

@@ -6,10 +6,6 @@
 module Que
   module Scheduler
     class DefinedJob < Hashie::Dash
-      QUE_SCHEDULER_CONFIG_LOCATION =
-        ENV.fetch('QUE_SCHEDULER_CONFIG_LOCATION', 'config/que_schedule.yml')
-      ERROR_MESSAGE_SUFFIX = "in que-scheduler config #{QUE_SCHEDULER_CONFIG_LOCATION}".freeze
-
       include Hashie::Extensions::Dash::PropertyTranslation
 
       SCHEDULE_TYPES = [
@@ -55,7 +51,8 @@ def calculate_missed_runs(last_run_time, as_time)
 
       class << self
         def defined_jobs
-          @defined_jobs ||= YAML.safe_load(IO.read(QUE_SCHEDULER_CONFIG_LOCATION)).map do |k, v|
+          schedule_string = IO.read(Que::Scheduler.configuration.schedule_location)
+          @defined_jobs ||= YAML.safe_load(schedule_string).map do |k, v|
             Que::Scheduler::DefinedJob.new(
               {
                 name: k,
@@ -73,7 +70,8 @@ def defined_jobs
         private
 
         def err_field(field, value)
-          raise "Invalid #{field} '#{value}' #{ERROR_MESSAGE_SUFFIX}"
+          schedule = Que::Scheduler.configuration.schedule_location
+          raise "Invalid #{field} '#{value}' in que-scheduler schedule #{schedule}"
         end
       end
 

lib/que/scheduler/migrations.rb

@@ -13,7 +13,7 @@ module Migrations
 
       class << self
         def migrate!(version:)
-          ::Que.transaction do
+          Que::Scheduler::Db.transaction do
             current = db_version
             if current < version
               migrate_up(current, version)

lib/que/scheduler/scheduler_job.rb

@@ -15,7 +15,7 @@ class SchedulerJob < Que::Job
       @priority = 0
 
       def run(options = nil)
-        ::Que.transaction do
+        Que::Scheduler::Db.transaction do
           assert_one_scheduler_job
           scheduler_job_args = SchedulerJobArgs.build(options)
           logs = ["que-scheduler last ran at #{scheduler_job_args.last_run_time}."]

lib/que/scheduler/version.rb

@@ -1,5 +1,5 @@
 module Que
   module Scheduler
-    VERSION = '3.0.0'.freeze
+    VERSION = '3.1.0'.freeze
   end
 end

spec/que/scheduler/db_spec.rb

@@ -34,5 +34,10 @@ def check(str)
     it 'Sequel is not used explicitly' do
       check('Sequel')
     end
+
+    # Check Que.transaction is not used, as the config transaction proc should be used instead
+    it 'Que.transaction is not used explicitly' do
+      check('Que.transaction')
+    end
   end
 end

spec/que/scheduler/defined_job_spec.rb

@@ -40,7 +40,7 @@ def expect_time(from, to, exp)
           job_class: 'HalfHourlyTestJob',
           cron: 'foo 17 * * *'
         )
-      end.to raise_error(/Invalid cron 'foo 17 \* \* \*' in que-scheduler config/)
+      end.to raise_error(/Invalid cron 'foo 17 \* \* \*' in que-scheduler schedule/)
     end
 
     it 'allows crons with fugit compatible english words' do
@@ -77,7 +77,7 @@ def expect_time(from, to, exp)
           job_class: 'HalfHourlyTestJob',
           queue: 3_214_214
         )
-      end.to raise_error(/Invalid queue '3214214' in que-scheduler config/)
+      end.to raise_error(/Invalid queue '3214214' in que-scheduler schedule/)
     end
 
     it 'checks the priority is an integer' do
@@ -87,7 +87,7 @@ def expect_time(from, to, exp)
           job_class: 'HalfHourlyTestJob',
           priority: 'foo'
         )
-      end.to raise_error(/Invalid priority 'foo' in que-scheduler config/)
+      end.to raise_error(/Invalid priority 'foo' in que-scheduler schedule/)
     end
 
     it 'checks the job_class is a Que::Job from job_class' do
@@ -96,7 +96,7 @@ def expect_time(from, to, exp)
           name: 'checking_job_types',
           job_class: 'NotAQueJob'
         )
-      end.to raise_error(/Invalid job_class 'NotAQueJob' in que-scheduler config/)
+      end.to raise_error(/Invalid job_class 'NotAQueJob' in que-scheduler schedule/)
     end
   end
 end

spec/spec_helper.rb

@@ -3,8 +3,6 @@
 require 'coveralls'
 Coveralls.wear!
 
-ENV['QUE_SCHEDULER_CONFIG_LOCATION'] = "#{__dir__}/config/que_schedule.yml"
-
 # By default, que-scheduler specs run in different timezones with every execution, thanks to
 # zonebie. If you want to force one particular timezone, you can use the following:
 # ENV['ZONEBIE_TZ'] = 'International Date Line West'
@@ -17,6 +15,10 @@
 
 Dir["#{__dir__}/../spec/support/**/*.rb"].each { |f| require f }
 
+Que::Scheduler.configure do |config|
+  config.schedule_location = "#{__dir__}/config/que_schedule.yml"
+end
+
 RSpec.configure do |config|
   config.example_status_persistence_file_path = '.rspec_status'
   config.disable_monkey_patching!