Handle a few jobs scheduled at the same time

Changes.md

@@ -1,24 +1,35 @@
-0.5.0
+0.8.0
 -----------
 
-- Initial release!
+- Added `on` (day of week) option to cronotab.rb semantic
+- Added job health check and job health indicator to the Web UI
 
-0.5.1
+
+0.7.0
 -----------
 
-- Added -e/--environment ENV option to set the daemon rails environment.
+- Added simple Web UI
 
-0.5.2
------------
-
-- Fix: Scheduled time now related to the last performing time.
 
 0.6.1
 -----------
 
 - Persist job state to your database.
 
-0.7.0
+
+0.5.2
 -----------
 
-- Added simple Web UI
+- Fix: Scheduled time now related to the last performing time.
+
+
+0.5.1
+-----------
+
+- Added -e/--environment ENV option to set the daemon rails environment.
+
+
+0.5.0
+-----------
+
+- Initial release!

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    crono (0.7.0)
+    crono (0.8.1)
       activejob (~> 4.0)
       activerecord (~> 4.0)
       activesupport (~> 4.0)
@@ -9,17 +9,17 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    activejob (4.2.0)
-      activesupport (= 4.2.0)
+    activejob (4.2.1)
+      activesupport (= 4.2.1)
       globalid (>= 0.3.0)
-    activemodel (4.2.0)
-      activesupport (= 4.2.0)
+    activemodel (4.2.1)
+      activesupport (= 4.2.1)
       builder (~> 3.1)
-    activerecord (4.2.0)
-      activemodel (= 4.2.0)
-      activesupport (= 4.2.0)
+    activerecord (4.2.1)
+      activemodel (= 4.2.1)
+      activesupport (= 4.2.1)
       arel (~> 6.0)
-    activesupport (4.2.0)
+    activesupport (4.2.1)
       i18n (~> 0.7)
       json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
@@ -44,6 +44,8 @@ GEM
     rack (1.6.0)
     rack-protection (1.5.3)
       rack
+    rack-test (0.6.3)
+      rack (>= 1.0)
     rake (10.4.2)
     rspec (3.2.0)
       rspec-core (~> 3.2.0)
@@ -64,7 +66,7 @@ GEM
       tilt (~> 1.3, >= 1.3.4)
     slop (3.6.0)
     sqlite3 (1.3.10)
-    thread_safe (0.3.4)
+    thread_safe (0.3.5)
     tilt (1.4.1)
     timecop (0.7.3)
     tzinfo (1.2.2)
@@ -78,6 +80,7 @@ DEPENDENCIES
   byebug
   crono!
   haml
+  rack-test
   rake (~> 10.0)
   rspec (~> 3.0)
   sinatra

README.md

@@ -9,12 +9,13 @@ Crono — Job scheduler for Rails
 Crono is a time-based background job scheduler daemon (just like Cron) for Ruby on Rails.
 
 
-## The Idea
+## The Purpose
 
-Currently there is no such thing as Cron in Ruby for Rails. Well, there's [Whenever](https://github.com/javan/whenever) but it works on top of Unix Cron, so you have no total control of it from Ruby. Crono is pure Ruby. It doesn't use Unix Cron and other platform-dependent things. So you can use it on all platforms supported by Ruby. It persists job state to your database using Active Record. You have full control of jobs performing process. You have Ruby code, so you can understand and modify it to fit your needs.
+Currently there is no such thing as Ruby Cron for Rails. Well, there's [Whenever](https://github.com/javan/whenever) but it works on top of Unix Cron, so you haven't control of it from Ruby. Crono is pure Ruby. It doesn't use Unix Cron and other platform-dependent things. So you can use it on all platforms supported by Ruby. It persists job states to your database using Active Record. You have full control of jobs performing process. It's Ruby, so you can understand and modify it to fit your needs.
 
 ![Web UI](https://github.com/plashchynski/crono/raw/master/examples/crono_web_ui.png)
 
+
 ## Requirements
 
 Tested with latest MRI Ruby (2.2, 2.1 and 2.0) and Rails 3.2+  
@@ -48,7 +49,7 @@ Now you are ready to move forward to create a job and schedule it.
 
 Crono can use Active Job jobs from `app/jobs/`. The only requirements is that the `perform` method should take no arguments.
 
-Here's an example of a test job:
+Here's an example of a job:
 
 ```ruby
 # app/jobs/test_job.rb
@@ -71,20 +72,23 @@ class TestJob # This is not an Active Job job, but pretty legal Crono job.
 end
 ```
 
+_Please note that crono uses threads, so your code should be thread-safe_
+
 #### Job Schedule
 
-The schedule described in the configuration file `config/cronotab.rb`, that created using `crono:install` or manually. The semantic is pretty straightforward:
+Schedule list is defined in the file `config/cronotab.rb`, that created using `crono:install`. The semantic is pretty straightforward:
 
 ```ruby
 # config/cronotab.rb
-Crono.perform(TestJob).every 2.days, at: "15:30"
+Crono.perform(TestJob).every 2.days, at: {hour: 15, min: 30}
+Crono.perform(TestJob).every 1.week, on: :monday, at: "15:30"
 ```
 
-You can schedule one job a few times, if you want a job to be performed a few times a day:
+You can schedule one job a few times, if you want the job to be performed a few times a day or a week:
 
 ```ruby
-Crono.perform(TestJob).every 1.day, at: "00:00"
-Crono.perform(TestJob).every 1.day, at: "12:00"
+Crono.perform(TestJob).every 1.week, on: :monday
+Crono.perform(TestJob).every 1.week, on: :thursday
 ```
 
 The `at` can be a Hash:
@@ -109,6 +113,7 @@ Usage: crono [options]
     -e, --environment ENV            Application environment (Default: development)
 ```
 
+
 ## Web UI
 
 Crono comes with a Sinatra application that can display the current state of Crono jobs.  
@@ -122,8 +127,6 @@ gem 'sinatra', require: nil
 Add the following to your `config/routes.rb`:
 
 ```ruby
-require 'crono/web'
-
 Rails.application.routes.draw do
     mount Crono::Web, at: '/crono'
     ...
@@ -131,6 +134,7 @@ Rails.application.routes.draw do
 
 Access management and other questions described in the [wiki](https://github.com/plashchynski/crono/wiki/Web-UI).
 
+
 ## Capistrano
 
 Use the `capistrano-crono` gem ([github](https://github.com/plashchynski/capistrano-crono/)).

bin/crono

@@ -1,8 +1,8 @@
 #!/usr/bin/env ruby
 
-$LOAD_PATH.unshift File.expand_path("../../lib", __FILE__)
+$LOAD_PATH.unshift File.expand_path('../../lib', __FILE__)
 
-require "crono/cli"
+require 'crono/cli'
 
 begin
   Crono::CLI.instance.run

crono.gemspec

@@ -2,30 +2,31 @@
 require File.expand_path('../lib/crono/version', __FILE__)
 
 Gem::Specification.new do |s|
-  s.name        = "crono"
+  s.name        = 'crono'
   s.version     = Crono::VERSION
-  s.authors     = ["Dzmitry Plashchynski"]
-  s.email       = ["plashchynski@gmail.com"]
-  s.homepage    = "https://github.com/plashchynski/crono"
-  s.description = s.summary = "Job scheduler for Rails"
-  s.license     = "Apache-2.0"
+  s.authors     = ['Dzmitry Plashchynski']
+  s.email       = ['plashchynski@gmail.com']
+  s.homepage    = 'https://github.com/plashchynski/crono'
+  s.description = s.summary = 'Job scheduler for Rails'
+  s.license     = 'Apache-2.0'
 
-  s.required_rubygems_version = ">= 1.3.6"
-  s.rubyforge_project         = "crono"
+  s.required_rubygems_version = '>= 1.3.6'
+  s.rubyforge_project         = 'crono'
 
-  s.add_runtime_dependency      "activejob", "~> 4.0"
-  s.add_runtime_dependency      "activesupport", "~> 4.0"
-  s.add_runtime_dependency      "activerecord", "~> 4.0"
-  s.add_development_dependency  "rake", "~> 10.0"
-  s.add_development_dependency  "bundler", ">= 1.0.0"
-  s.add_development_dependency  "rspec", "~> 3.0"
-  s.add_development_dependency  "timecop", "~> 0.7"
-  s.add_development_dependency  "sqlite3"
-  s.add_development_dependency  "byebug"
-  s.add_development_dependency  "sinatra"
-  s.add_development_dependency  "haml"
+  s.add_runtime_dependency 'activejob', '~> 4.0'
+  s.add_runtime_dependency 'activesupport', '~> 4.0'
+  s.add_runtime_dependency 'activerecord', '~> 4.0'
+  s.add_development_dependency 'rake', '~> 10.0'
+  s.add_development_dependency 'bundler', '>= 1.0.0'
+  s.add_development_dependency 'rspec', '~> 3.0'
+  s.add_development_dependency 'timecop', '~> 0.7'
+  s.add_development_dependency 'sqlite3'
+  s.add_development_dependency 'byebug'
+  s.add_development_dependency 'sinatra'
+  s.add_development_dependency 'haml'
+  s.add_development_dependency 'rack-test'
 
   s.files        = `git ls-files`.split("\n")
-  s.executables  = `git ls-files`.split("\n").map{|f| f =~ /^bin\/(.*)/ ? $1 : nil}.compact
+  s.executables  = ['crono']
   s.require_path = 'lib'
 end

examples/cronotab.rb

@@ -1,4 +1,4 @@
-# cronotab.rb — Crono configuration file
+# cronotab.rb - Crono configuration file
 #
 # Here you can specify periodic jobs and schedule.
 # You can use ActiveJob's jobs from `app/jobs/`
@@ -7,9 +7,8 @@
 #
 class TestJob
   def perform
-    puts "Test!"
+    puts 'Test!'
   end
 end
 
-Crono.perform(TestJob).every 2.days, at: "15:30"
-
+Crono.perform(TestJob).every 2.days, at: '15:30'

lib/crono.rb

@@ -1,12 +1,16 @@
+# Crono main module
 module Crono
 end
 
-require "active_support/all"
-require "crono/version.rb"
-require "crono/logging.rb"
-require "crono/period.rb"
-require "crono/job.rb"
-require "crono/scheduler.rb"
-require "crono/config.rb"
-require "crono/performer_proxy.rb"
-require "crono/orm/active_record/crono_job.rb"
+require 'active_support/all'
+require 'crono/version'
+require 'crono/logging'
+require 'crono/period'
+require 'crono/job'
+require 'crono/scheduler'
+require 'crono/config'
+require 'crono/performer_proxy'
+require 'crono/orm/active_record/crono_job'
+require 'crono/railtie' if defined?(Rails)
+
+Crono.autoload :Web, 'crono/web'

lib/crono/cli.rb

@@ -2,8 +2,7 @@ require 'crono'
 require 'optparse'
 
 module Crono
-  mattr_accessor :scheduler
-
+  # Crono::CLI - The main class for the crono daemon exacutable `bin/crono`
   class CLI
     include Singleton
     include Logging
@@ -18,12 +17,7 @@ module Crono
     def run
       parse_options(ARGV)
 
-      if config.daemonize
-        set_log_to(config.logfile)
-        daemonize 
-      else
-        set_log_to(STDOUT)
-      end
+      setup_log
 
       write_pid
       load_rails
@@ -33,7 +27,17 @@ module Crono
       start_working_loop
     end
 
-  private
+    private
+
+    def setup_log
+      if config.daemonize
+        self.logfile = config.logfile
+        daemonize
+      else
+        self.logfile = STDOUT
+      end
+    end
+
     def daemonize
       ::Process.daemon(true, true)
 
@@ -42,7 +46,7 @@ module Crono
         io.sync = true
       end
 
-      $stdin.reopen("/dev/null")
+      $stdin.reopen('/dev/null')
     end
 
     def write_pid
@@ -54,30 +58,31 @@ module Crono
       logger.info "Loading Crono #{Crono::VERSION}"
       logger.info "Running in #{RUBY_DESCRIPTION}"
 
-      logger.info "Jobs:"
+      logger.info 'Jobs:'
       Crono.scheduler.jobs.each do |job|
-        logger.info %{"#{job.performer}" with rule "#{job.period.description}" next time will perform at #{job.next}}
+        logger.info "'#{job.performer}' with rule '#{job.period.description}'"\
+                    "next time will perform at #{job.next}"
       end
     end
 
     def load_rails
       ENV['RACK_ENV'] = ENV['RAILS_ENV'] = config.environment
       require 'rails'
-      require File.expand_path("config/environment.rb")
+      require File.expand_path('config/environment.rb')
       ::Rails.application.eager_load!
       require File.expand_path(config.cronotab)
     end
 
     def check_jobs
-      if Crono.scheduler.jobs.empty?
-        logger.error "You have no jobs defined in you cronotab file #{config.cronotab}"
-      end
+      return if Crono.scheduler.jobs.present?
+      logger.error "You have no jobs in you cronotab file #{config.cronotab}"
     end
 
     def start_working_loop
-      while job = Crono.scheduler.next do
-        sleep(job.next - Time.now)
-        job.perform
+      while true
+        next_time, jobs = Crono.scheduler.next_jobs
+        sleep(next_time - Time.now)
+        jobs.each(&:perform)
       end
     end
 

lib/crono/config.rb

@@ -1,21 +1,18 @@
 module Crono
+  # Crono::Config stores Crono configuration
   class Config
-    CRONOTAB  = "config/cronotab.rb"
-    LOGFILE   = "log/crono.log"
-    PIDFILE   = "tmp/pids/crono.pid"
+    CRONOTAB  = 'config/cronotab.rb'
+    LOGFILE   = 'log/crono.log'
+    PIDFILE   = 'tmp/pids/crono.pid'
 
-    attr_accessor :cronotab
-    attr_accessor :logfile
-    attr_accessor :pidfile
-    attr_accessor :daemonize
-    attr_accessor :environment
+    attr_accessor :cronotab, :logfile, :pidfile, :daemonize, :environment
 
     def initialize
       self.cronotab = CRONOTAB
       self.logfile  = LOGFILE
       self.pidfile  = PIDFILE
       self.daemonize = false
-      self.environment = ENV['RAILS_ENV'] || ENV['RACK_ENV'] || "development"
+      self.environment = ENV['RAILS_ENV'] || ENV['RACK_ENV'] || 'development'
     end
   end
 end

lib/crono/job.rb

@@ -2,14 +2,12 @@ require 'stringio'
 require 'logger'
 
 module Crono
+  # Crono::Job represents a Crono job
   class Job
     include Logging
 
-    attr_accessor :performer
-    attr_accessor :period
-    attr_accessor :last_performed_at
-    attr_accessor :job_log
-    attr_accessor :job_logger
+    attr_accessor :performer, :period, :last_performed_at, :job_log,
+                  :job_logger, :healthy
 
     def initialize(performer, period)
       self.performer, self.period = performer, period
@@ -19,8 +17,7 @@ module Crono
     end
 
     def next
-      next_time = period.next(since: last_performed_at)
-      next_time.past? ? period.next : next_time
+      period.next(since: last_performed_at)
     end
 
     def description
@@ -35,26 +32,13 @@ module Crono
       log "Perform #{performer}"
       self.last_performed_at = Time.now
 
-      Thread.new do
-        begin
-          performer.new.perform
-        rescue Exception => e
-          log "Finished #{performer} in %.2f seconds with error: #{e.message}" % (Time.now - last_performed_at)
-          log e.backtrace.join("\n")
-        else
-          log "Finished #{performer} in %.2f seconds" % (Time.now - last_performed_at)
-        ensure
-          save
-        end
-      end
+      Thread.new { perform_job }
     end
 
     def save
       @semaphore.synchronize do
-        log = model.reload.log || ""
-        log << job_log.string
-        job_log.truncate(job_log.rewind)
-        model.update(last_performed_at: last_performed_at, log: log)
+        update_model
+        clear_job_log
       end
     end
 
@@ -62,11 +46,52 @@ module Crono
       self.last_performed_at = model.last_performed_at
     end
 
-  private
-    def log(message)
+    private
+
+    def clear_job_log
+      job_log.truncate(job_log.rewind)
+    end
+
+    def update_model
+      saved_log = model.reload.log || ''
+      log_to_save = saved_log + job_log.string
+      model.update(last_performed_at: last_performed_at, log: log_to_save,
+                   healthy: healthy)
+    end
+
+    def perform_job
+      performer_instance = performer.new
+      performer_instance.instance_variable_set(:@_crono_job, self)
+      performer_instance.perform
+      finished_time_sec = format('%.2f', Time.now - last_performed_at)
+    rescue StandardError => e
+      handle_job_fail(e, finished_time_sec)
+    else
+      handle_job_success(finished_time_sec)
+    ensure
+      save
+    end
+
+    def handle_job_fail(exception, finished_time_sec)
+      self.healthy = false
+      log_error "Finished #{performer} in #{finished_time_sec} seconds"\
+                "with error: #{exception.message}"
+      log_error exception.backtrace.join("\n")
+    end
+
+    def handle_job_success(finished_time_sec)
+      self.healthy = true
+      log "Finished #{performer} in #{finished_time_sec} seconds"
+    end
+
+    def log_error(message)
+      log(message, Logger::ERROR)
+    end
+
+    def log(message, severity = Logger::INFO)
       @semaphore.synchronize do
-        logger.info message
-        job_logger.info message
+        logger.log severity, message
+        job_logger.log severity, message
       end
     end
 

lib/crono/logging.rb

@@ -1,8 +1,9 @@
 module Crono
   mattr_accessor :logger
 
+  # Crono::Logging is a standart Ruby logger wrapper
   module Logging
-    def set_log_to(logfile)
+    def logfile=(logfile)
       Crono.logger = Logger.new(logfile)
     end
 

lib/crono/orm/active_record/crono_job.rb

@@ -1,8 +1,13 @@
 require 'active_record'
 
 module Crono
+  # Crono::CronoJob is a ActiveRecord model to store job state
   class CronoJob < ActiveRecord::Base
-    self.table_name = "crono_jobs"
+    self.table_name = 'crono_jobs'
     validates :job_id, presence: true, uniqueness: true
+
+    def self.outdated
+      self
+    end
   end
 end

lib/crono/performer_proxy.rb

@@ -1,4 +1,5 @@
 module Crono
+  # Crono::PerformerProxy is a proxy used in cronotab.rb semantic
   class PerformerProxy
     def initialize(performer, scheduler)
       @performer = performer

lib/crono/period.rb

@@ -1,27 +1,53 @@
 module Crono
+  # Period describe frequency of performing a task
   class Period
-    def initialize(period, at: nil)
+    DAYS = [:monday, :tuesday, :wednesday, :thursday, :friday, :saturday,
+            :sunday]
+
+    def initialize(period, at: nil, on: nil)
       @period = period
       @at_hour, @at_min = parse_at(at) if at
+      @on = parse_on(on) if on
     end
 
     def next(since: nil)
-      if since.nil?
-        @next = Time.now.change(time_atts)
-        return @next if @next.future?
-        since = Time.now
-      end
-
-      @period.since(since).change(time_atts)
+      return initial_next unless since
+      @next = @period.since(since)
+      @next = @next.beginning_of_week.advance(days: @on) if @on
+      @next.change(time_atts)
     end
 
     def description
       desc = "every #{@period.inspect}"
-      desc += " at %.2i:%.2i" % [@at_hour, @at_min] if @at_hour && @at_min
+      desc += format(' at %.2i:%.2i', @at_hour, @at_min) if @at_hour && @at_min
+      desc += " on #{DAYS[@on].capitalize}" if @on
       desc
     end
 
+    private
+
+    def initial_next
+      next_time = initial_day.change(time_atts)
+      return next_time if next_time.future?
+      @period.from_now.change(time_atts)
+    end
+
+    def initial_day
+      return Time.now unless @on
+      day = Time.now.beginning_of_week.advance(days: @on)
+      return day if day.future?
+      @period.from_now.beginning_of_week.advance(days: @on)
+    end
+
+    def parse_on(on)
+      day_number = DAYS.index(on)
+      fail "Wrong 'on' day" unless day_number
+      fail "period should be at least 1 week to use 'on'" if @period < 1.week
+      day_number
+    end
+
     def parse_at(at)
+      fail "period should be at least 1 day to use 'at'" if @period < 1.day
       case at
       when String
         time = Time.parse(at)
@@ -29,13 +55,12 @@ module Crono
       when Hash
         return at[:hour], at[:min]
       else
-        raise "Unknown 'at' format"
+        fail "Unknown 'at' format"
       end
     end
 
-  private
     def time_atts
-      {hour: @at_hour, min: @at_min}.compact
+      { hour: @at_hour, min: @at_min }.compact
     end
   end
 end

lib/crono/railtie.rb

@@ -0,0 +1,9 @@
+module Crono
+  class Railtie < ::Rails::Railtie
+    rake_tasks do
+      Dir[File.join(File.dirname(__FILE__), '../tasks/*.rake')].each do |file|
+        load file
+      end
+    end
+  end
+end

lib/crono/scheduler.rb

@@ -1,4 +1,5 @@
 module Crono
+  # Scheduler is a container for job list and queue
   class Scheduler
     attr_accessor :jobs
 
@@ -11,13 +12,10 @@ module Crono
       jobs << job
     end
 
-    def next
-      queue.first
-    end
-
-  private
-    def queue
-      jobs.sort_by(&:next)
+    def next_jobs
+      jobs.group_by(&:next).sort_by {|time,_| time }.first
     end
   end
+
+  mattr_accessor :scheduler
 end

lib/crono/version.rb

@@ -1,3 +1,3 @@
 module Crono
-  VERSION = '0.7.0'
+  VERSION = '0.8.1'
 end

lib/crono/web.rb

@@ -1,18 +1,20 @@
 require 'haml'
 require 'sinatra/base'
+require 'crono'
 
 module Crono
+  # Web is a Web UI Sinatra app
   class Web < Sinatra::Base
-    set :root, File.expand_path(File.dirname(__FILE__) + "/../../web")
-    set :public_folder, Proc.new { "#{root}/assets" }
-    set :views, Proc.new { "#{root}/views" }
+    set :root, File.expand_path(File.dirname(__FILE__) + '/../../web')
+    set :public_folder, proc { "#{root}/assets" }
+    set :views, proc { "#{root}/views" }
 
     get '/' do
       @jobs = Crono::CronoJob.all
       haml :dashboard, format: :html5
     end
 
-    get '/jobs/:id' do
+    get '/job/:id' do
       @job = Crono::CronoJob.find(params[:id])
       haml :job
     end

lib/generators/crono/install/install_generator.rb

@@ -4,6 +4,7 @@ require 'rails/generators/active_record'
 
 module Crono
   module Generators
+    # rails generate crono:install
     class InstallGenerator < ::Rails::Generators::Base
       include Rails::Generators::Migration
 
@@ -11,15 +12,16 @@ module Crono
         ActiveRecord::Generators::Base.next_migration_number(path)
       end
 
-      desc "Installs crono and generates the necessary configuration files"
-      source_root File.expand_path("../templates", __FILE__)
+      desc 'Installs crono and generates the necessary configuration files'
+      source_root File.expand_path('../templates', __FILE__)
 
       def copy_config
         template 'cronotab.rb.erb', 'config/cronotab.rb'
       end
 
       def create_migrations
-        migration_template 'migrations/create_crono_jobs.rb', 'db/migrate/create_crono_jobs.rb'
+        migration_template 'migrations/create_crono_jobs.rb',
+                           'db/migrate/create_crono_jobs.rb'
       end
     end
   end

lib/generators/crono/install/templates/cronotab.rb.erb

@@ -7,9 +7,9 @@
 #
 # class TestJob
 #   def perform
-#     puts "Test!"
+#     puts 'Test!'
 #   end
 # end
 #
-# Crono.perform(TestJob).every 2.days, at: "15:30"
+# Crono.perform(TestJob).every 2.days, at: '15:30'
 #

lib/generators/crono/install/templates/migrations/create_crono_jobs.rb

@@ -4,6 +4,7 @@ class CreateCronoJobs < ActiveRecord::Migration
       t.string    :job_id, null: false
       t.text      :log
       t.datetime  :last_performed_at
+      t.boolean   :healthy
       t.timestamps null: false
     end
     add_index :crono_jobs, [:job_id], unique: true

lib/tasks/crono_tasks.rake

@@ -0,0 +1,26 @@
+module Crono
+  def self.load_cronotab
+    cronotab_path = ENV['CRONOTAB'] || (defined?(Rails) &&
+                      File.join(Rails.root, cronotab_path))
+    fail 'No cronotab defined' unless cronotab_path
+    puts "Load cronotab #{cronotab_path}"
+    require cronotab_path
+  end
+end
+
+namespace :crono do
+  desc 'Clean unused job stats from DB'
+  task clean: :environment do
+    Crono.scheduler = Crono::Scheduler.new
+    Crono.load_cronotab
+    current_job_ids = Crono.scheduler.jobs.map(&:job_id)
+    Crono::CronoJob.where.not(job_id: current_job_ids).destroy_all
+  end
+
+  desc 'Check cronotab.rb syntax'
+  task check: :environment do
+    Crono.scheduler = Crono::Scheduler.new
+    Crono.load_cronotab
+    puts 'Syntax ok'
+  end
+end

spec/assets/bad_cronotab.rb

@@ -0,0 +1,12 @@
+# This is an example of a bad cronotab for tests
+
+class TestJob
+  def perform
+    puts 'Test!'
+  end
+end
+
+# This is an error, because you can use `on` options with
+# a period less than 7 days.
+
+Crono.perform(TestJob).every 5.days, on: :sunday

spec/assets/good_cronotab.rb

@@ -0,0 +1,9 @@
+# This is an example of a good cronotab for tests
+
+class TestJob
+  def perform
+    puts 'Test!'
+  end
+end
+
+Crono.perform(TestJob).every 5.seconds

spec/cli_spec.rb

@@ -1,15 +1,11 @@
-require "spec_helper"
+require 'spec_helper'
 require 'crono/cli'
 
-class TestJob
-  def perform;end
-end
-
 describe Crono::CLI do
   let(:cli) { Crono::CLI.instance }
 
-  describe "#run" do
-    it "should try to initialize rails with #load_rails and start working loop" do
+  describe '#run' do
+    it 'should initialize rails with #load_rails and start working loop' do
       expect(cli).to receive(:load_rails)
       expect(cli).to receive(:start_working_loop)
       expect(cli).to receive(:parse_options)
@@ -18,34 +14,30 @@ describe Crono::CLI do
     end
   end
 
-  describe "#start_working_loop" do
-    it "should start working loop"
-  end
-
-  describe "#parse_options" do
-    it "should set cronotab" do
-      cli.send(:parse_options, ["--cronotab", "/tmp/cronotab.rb"])
-      expect(cli.config.cronotab).to be_eql "/tmp/cronotab.rb"
+  describe '#parse_options' do
+    it 'should set cronotab' do
+      cli.send(:parse_options, ['--cronotab', '/tmp/cronotab.rb'])
+      expect(cli.config.cronotab).to be_eql '/tmp/cronotab.rb'
     end
 
-    it "should set logfile" do
-      cli.send(:parse_options, ["--logfile", "log/crono.log"])
-      expect(cli.config.logfile).to be_eql "log/crono.log"
+    it 'should set logfile' do
+      cli.send(:parse_options, ['--logfile', 'log/crono.log'])
+      expect(cli.config.logfile).to be_eql 'log/crono.log'
     end
 
-    it "should set pidfile" do
-      cli.send(:parse_options, ["--pidfile", "tmp/pids/crono.0.log"])
-      expect(cli.config.pidfile).to be_eql "tmp/pids/crono.0.log"
+    it 'should set pidfile' do
+      cli.send(:parse_options, ['--pidfile', 'tmp/pids/crono.0.log'])
+      expect(cli.config.pidfile).to be_eql 'tmp/pids/crono.0.log'
     end
 
-    it "should set daemonize" do
-      cli.send(:parse_options, ["--daemonize"])
+    it 'should set daemonize' do
+      cli.send(:parse_options, ['--daemonize'])
       expect(cli.config.daemonize).to be true
     end
 
-    it "should set environment" do
-      cli.send(:parse_options, ["--environment", "production"])
-      expect(cli.config.environment).to be_eql("production")
+    it 'should set environment' do
+      cli.send(:parse_options, ['--environment', 'production'])
+      expect(cli.config.environment).to be_eql('production')
     end
   end
 end

spec/config_spec.rb

@@ -1,15 +1,15 @@
-require "spec_helper"
+require 'spec_helper'
 
 describe Crono::Config do
-  describe "#initialize" do
-    it "should initialize with default configuration options" do
-      ENV["RAILS_ENV"] = "test"
+  describe '#initialize' do
+    it 'should initialize with default configuration options' do
+      ENV['RAILS_ENV'] = 'test'
       @config = Crono::Config.new
       expect(@config.cronotab).to be Crono::Config::CRONOTAB
       expect(@config.logfile).to be Crono::Config::LOGFILE
       expect(@config.pidfile).to be Crono::Config::PIDFILE
       expect(@config.daemonize).to be false
-      expect(@config.environment).to be_eql ENV["RAILS_ENV"]
+      expect(@config.environment).to be_eql ENV['RAILS_ENV']
     end
   end
 end

spec/job_spec.rb

@@ -1,63 +1,80 @@
-require "spec_helper"
-
-class TestJob
-  def perform;end
-end
-
-class TestFailingJob
-  def perform
-    raise "Some error"
-  end
-end
+require 'spec_helper'
 
 describe Crono::Job do
-  let(:period) { Crono::Period.new(2.day) }
-  let(:job) { Crono::Job.new(TestJob, period) } 
+  let(:period) { Crono::Period.new(2.day, at: '15:00') }
+  let(:job) { Crono::Job.new(TestJob, period) }
   let(:failing_job) { Crono::Job.new(TestFailingJob, period) }
 
-  it "should contain performer and period" do
+  it 'should contain performer and period' do
     expect(job.performer).to be TestJob
     expect(job.period).to be period
   end
 
-  describe "#perform" do
-    it "should run performer in separate thread" do
+  describe '#next' do
+    it 'should return next performing time according to period' do
+      expect(job.next).to be_eql period.next
+    end
+  end
+
+  describe '#perform' do
+    after { job.send(:model).destroy }
+
+    it 'should run performer in separate thread' do
       expect(job).to receive(:save)
       thread = job.perform.join
       expect(thread).to be_stop
-      job.send(:model).destroy
     end
 
-    it "should save performin errors to log" do
+    it 'should save performin errors to log' do
       thread = failing_job.perform.join
       expect(thread).to be_stop
       saved_log = Crono::CronoJob.find_by(job_id: failing_job.job_id).log
-      expect(saved_log).to include "Some error"
+      expect(saved_log).to include 'Some error'
+    end
+
+    xit 'should set Job#healthy to true if perform ok' do
+      class TestJob
+        def perform
+          @_crono_job
+        end
+      end
+      job.perform.join
+    end
+
+    it 'should set Job#healthy to false if perform with error' do
+      failing_job.perform.join
+      expect(failing_job.healthy).to be false
+    end
+
+    xit 'should set @_crono_job variable to instance' do
+      job.perform
     end
   end
 
-  describe "#description" do
-    it "should return job identificator" do
-      expect(job.description).to be_eql("Perform TestJob every 2 days")
+  describe '#description' do
+    it 'should return job identificator' do
+      expect(job.description).to be_eql('Perform TestJob every 2 days at 15:00')
     end
   end
 
-  describe "#save" do
-    it "should save new job to DB" do
+  describe '#save' do
+    it 'should save new job to DB' do
       expect(Crono::CronoJob.where(job_id: job.job_id)).to_not exist
       job.save
       expect(Crono::CronoJob.where(job_id: job.job_id)).to exist
     end
 
-    it "should update saved job" do
+    it 'should update saved job' do
       job.last_performed_at = Time.now
+      job.healthy = true
       job.save
       @crono_job = Crono::CronoJob.find_by(job_id: job.job_id)
       expect(@crono_job.last_performed_at.utc.to_s).to be_eql job.last_performed_at.utc.to_s
+      expect(@crono_job.healthy).to be true
     end
 
-    it "should save and truncate job log" do
-      message = "test message"
+    it 'should save and truncate job log' do
+      message = 'test message'
       job.send(:log, message)
       job.save
       expect(job.send(:model).reload.log).to include message
@@ -65,31 +82,39 @@ describe Crono::Job do
     end
   end
 
-  describe "#load" do
+  describe '#load' do
     before do
       @saved_last_performed_at = job.last_performed_at = Time.now
       job.save
     end
 
-    it "should load last_performed_at from DB" do
+    it 'should load last_performed_at from DB' do
       @job = Crono::Job.new(TestJob, period)
       @job.load
       expect(@job.last_performed_at.utc.to_s).to be_eql @saved_last_performed_at.utc.to_s
     end
   end
 
-  describe "#log" do
-    it "should write log messages to both common and job log" do
-      message = "Test message"
-      expect(job.logger).to receive(:info).with(message)
-      expect(job.job_logger).to receive(:info).with(message)
+  describe '#log' do
+    it 'should write log messages to both common and job log' do
+      message = 'Test message'
+      expect(job.logger).to receive(:log).with(Logger::INFO, message)
+      expect(job.job_logger).to receive(:log).with(Logger::INFO, message)
       job.send(:log, message)
     end
 
-    it "should write job log to Job#job_log" do
-      message = "Test message"
+    it 'should write job log to Job#job_log' do
+      message = 'Test message'
       job.send(:log, message)
       expect(job.job_log.string).to include(message)
     end
   end
+
+  describe '#log_error' do
+    it 'should call log with ERROR severity' do
+      message = 'Test message'
+      expect(job).to receive(:log).with(message, Logger::ERROR)
+      job.send(:log_error, message)
+    end
+  end
 end

spec/orm/active_record/crono_job_spec.rb

@@ -1,26 +1,26 @@
-require "spec_helper"
+require 'spec_helper'
 
 describe Crono::CronoJob do
   let(:valid_attrs) do
     {
-      job_id: "Perform TestJob every 3 days"
+      job_id: 'Perform TestJob every 3 days'
     }
   end
 
-  it "should validate presence of job_id" do
-    @crono_job = Crono::CronoJob.new()
+  it 'should validate presence of job_id' do
+    @crono_job = Crono::CronoJob.new
     expect(@crono_job).not_to be_valid
     expect(@crono_job.errors.added?(:job_id, :blank)).to be true
   end
 
-  it "should validate uniqueness of job_id" do
-    Crono::CronoJob.create!(job_id: "TestJob every 2 days")
-    @crono_job = Crono::CronoJob.create(job_id: "TestJob every 2 days")
+  it 'should validate uniqueness of job_id' do
+    Crono::CronoJob.create!(job_id: 'TestJob every 2 days')
+    @crono_job = Crono::CronoJob.create(job_id: 'TestJob every 2 days')
     expect(@crono_job).not_to be_valid
     expect(@crono_job.errors.added?(:job_id, :taken)).to be true
   end
 
-  it "should save job_id to DB" do
+  it 'should save job_id to DB' do
     Crono::CronoJob.create!(valid_attrs)
     @crono_job = Crono::CronoJob.find_by(job_id: valid_attrs[:job_id])
     expect(@crono_job).to be_present

spec/performer_proxy_spec.rb

@@ -1,12 +1,8 @@
-require "spec_helper"
-
-class TestJob
-  def perform;end
-end
+require 'spec_helper'
 
 describe Crono::PerformerProxy do
-  it "should add job to schedule" do
+  it 'should add job to schedule' do
     expect(Crono.scheduler).to receive(:add_job).with(kind_of(Crono::Job))
-    Crono.perform(TestJob).every(2.days, at: "15:30")
+    Crono.perform(TestJob).every(2.days, at: '15:30')
   end
 end

spec/period_spec.rb

@@ -1,4 +1,4 @@
-require "spec_helper"
+require 'spec_helper'
 
 describe Crono::Period do
   around(:each) do |example|
@@ -7,49 +7,93 @@ describe Crono::Period do
     end
   end
 
-  describe "#description" do
-    it "should return period description" do
-      @period = Crono::Period.new(2.day, at: "15:20")
-      expect(@period.description).to be_eql("every 2 days at 15:20")
+  describe '#description' do
+    it 'should return period description' do
+      @period = Crono::Period.new(1.week, on: :monday, at: '15:20')
+      expect(@period.description).to be_eql('every 7 days at 15:20 on Monday')
     end
   end
 
-  describe "#next" do
-    context "in daily basis" do
-      it "should return the time 2 days from now" do
+  describe '#next' do
+    context 'in weakly basis' do
+      it "should raise error if 'on' is wrong" do
+        expect { @period = Crono::Period.new(7.days, on: :bad_day) }
+          .to raise_error("Wrong 'on' day")
+      end
+
+      it 'should raise error when period is less than 1 week' do
+        expect { @period = Crono::Period.new(6.days, on: :monday) }
+          .to raise_error("period should be at least 1 week to use 'on'")
+      end
+
+      it "should return a 'on' day" do
+        @period = Crono::Period.new(1.week, on: :thursday, at: '15:30')
+        current_week = Time.now.beginning_of_week
+        last_run_time = current_week.advance(days: 1) # last run on the tuesday
+        next_run_at = Time.now.next_week.advance(days: 3)
+                      .change(hour: 15, min: 30)
+        expect(@period.next(since: last_run_time)).to be_eql(next_run_at)
+      end
+
+      it "should return a next week day 'on'" do
+        @period = Crono::Period.new(1.week, on: :thursday)
+        Timecop.freeze(Time.now.beginning_of_week.advance(days: 4)) do
+          expect(@period.next).to be_eql(Time.now.next_week.advance(days: 3))
+        end
+      end
+
+      it 'should return a current week day on the first run if not too late' do
+        @period = Crono::Period.new(7.days, on: :tuesday)
+        beginning_of_the_week = Time.now.beginning_of_week
+        tuesday = beginning_of_the_week.advance(days: 1)
+        Timecop.freeze(beginning_of_the_week) do
+          expect(@period.next).to be_eql(tuesday)
+        end
+      end
+    end
+
+    context 'in daily basis' do
+      it 'should return the time 2 days from now' do
         @period = Crono::Period.new(2.day)
         expect(@period.next).to be_eql(2.day.from_now)
       end
 
       it "should set time to 'at' time as a string" do
         time = 10.minutes.ago
-        @period = Crono::Period.new(2.day, at: [time.hour, time.min].join(':'))
+        at = [time.hour, time.min].join(':')
+        @period = Crono::Period.new(2.day, at: at)
         expect(@period.next).to be_eql(2.day.from_now.change(hour: time.hour, min: time.min))
       end
 
       it "should set time to 'at' time as a hash" do
         time = 10.minutes.ago
-        at = {hour: time.hour, min: time.min}
+        at = { hour: time.hour, min: time.min }
         @period = Crono::Period.new(2.day, at: at)
         expect(@period.next).to be_eql(2.day.from_now.change(at))
       end
 
       it "should raise error when 'at' is wrong" do
         expect {
-          @period = Crono::Period.new(2.day, at: 1)
+          Crono::Period.new(2.day, at: 1)
         }.to raise_error("Unknown 'at' format")
       end
 
-      it "should return time in relation to last time" do
+      it 'should raise error when period is less than 1 day' do
+        expect {
+          Crono::Period.new(5.hours, at: '15:30')
+        }.to raise_error("period should be at least 1 day to use 'at'")
+      end
+
+      it 'should return time in relation to last time' do
         @period = Crono::Period.new(2.day)
         expect(@period.next(since: 1.day.ago)).to be_eql(1.day.from_now)
       end
 
-      it "should return today time if it is first run and not too late" do
+      it 'should return today time if it is first run and not too late' do
         time = 10.minutes.from_now
-        at = {hour: time.hour, min: time.min}
+        at = { hour: time.hour, min: time.min }
         @period = Crono::Period.new(2.day, at: at)
-        expect(@period.next).to be_eql(Time.now.change(at))
+        expect(@period.next.utc.to_s).to be_eql(Time.now.change(at).utc.to_s)
       end
     end
   end

spec/scheduler_spec.rb

@@ -1,31 +1,38 @@
-require "spec_helper"
-
-class TestJob
-  def perform;end
-end
+require 'spec_helper'
 
 describe Crono::Scheduler do
-  before(:each) do
-    @scheduler = Crono::Scheduler.new
-    @jobs = [
-      Crono::Period.new(3.day, at: 10.minutes.from_now.strftime("%H:%M")),
-      Crono::Period.new(1.day, at: 20.minutes.from_now.strftime("%H:%M")),
-      Crono::Period.new(7.day, at: 40.minutes.from_now.strftime("%H:%M"))
-    ].map { |period| Crono::Job.new(TestJob, period) }
-    @scheduler.jobs = @jobs
-  end
+  let(:scheduler) { Crono::Scheduler.new }
 
-  describe "#add_job" do
-    it "should call Job#load on Job" do
-      @job = Crono::Job.new(TestJob, Crono::Period.new(10.day, at: "04:05"))
+  describe '#add_job' do
+    it 'should call Job#load on Job' do
+      @job = Crono::Job.new(TestJob, Crono::Period.new(10.day, at: '04:05'))
       expect(@job).to receive(:load)
-      @scheduler.add_job(@job)
+      scheduler.add_job(@job)
     end
   end
 
-  describe "#next" do
-    it "should return next job in schedule" do
-      expect(@scheduler.next).to be @jobs[0]
+  describe '#next_jobs' do
+    it 'should return next job in schedule' do
+      scheduler.jobs = jobs = [
+        Crono::Period.new(3.days, at: 10.minutes.from_now.strftime('%H:%M')),
+        Crono::Period.new(1.day, at: 20.minutes.from_now.strftime('%H:%M')),
+        Crono::Period.new(7.days, at: 40.minutes.from_now.strftime('%H:%M'))
+      ].map { |period| Crono::Job.new(TestJob, period) }
+
+      time, jobs = scheduler.next_jobs
+      expect(jobs).to be_eql [jobs[0]]
+    end
+
+    it 'should return an array of jobs scheduled at same time' do
+      time = 5.minutes.from_now
+      scheduler.jobs = jobs = [
+        Crono::Period.new(1.day, at: time.strftime('%H:%M')),
+        Crono::Period.new(1.day, at: time.strftime('%H:%M')),
+        Crono::Period.new(1.day, at: 10.minutes.from_now.strftime('%H:%M'))
+      ].map { |period| Crono::Job.new(TestJob, period) }
+
+      time, jobs = scheduler.next_jobs
+      expect(jobs).to be_eql [jobs[0], jobs[1]]
     end
   end
 end

spec/spec_helper.rb

@@ -6,9 +6,21 @@ require 'byebug'
 require 'crono'
 require 'generators/crono/install/templates/migrations/create_crono_jobs.rb'
 
-ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: "file::memory:?cache=shared")
+ActiveRecord::Base.establish_connection(
+  adapter: 'sqlite3',
+  database: 'file::memory:?cache=shared'
+)
+
 ActiveRecord::Base.logger = Logger.new(STDOUT)
 CreateCronoJobs.up
 
-RSpec.configure do |config|
+class TestJob
+  def perform
+  end
+end
+
+class TestFailingJob
+  def perform
+    fail 'Some error'
+  end
 end

spec/tasks/crono_tasks_spec.rb

@@ -0,0 +1,23 @@
+require 'spec_helper'
+require 'rake'
+
+load 'tasks/crono_tasks.rake'
+Rake::Task.define_task(:environment)
+
+describe 'rake' do
+  describe 'crono:clean' do
+    it 'should clean unused tasks from DB' do
+      Crono::CronoJob.create!(job_id: 'used_job')
+      ENV['CRONOTAB'] = File.expand_path('../../assets/good_cronotab.rb', __FILE__)
+      Rake::Task['crono:clean'].invoke
+      expect(Crono::CronoJob.where(job_id: 'used_job')).not_to exist
+    end
+  end
+
+  describe 'crono:check' do
+    it 'should check cronotab syntax' do
+      ENV['CRONOTAB'] = File.expand_path('../../assets/bad_cronotab.rb', __FILE__)
+      expect { Rake::Task['crono:check'].invoke }.to raise_error
+    end
+  end
+end

spec/web_spec.rb

@@ -0,0 +1,49 @@
+require 'spec_helper'
+require 'rack/test'
+include Rack::Test::Methods
+
+describe Crono::Web do
+  let(:app) { Crono::Web }
+
+  before do
+    Crono::CronoJob.destroy_all
+    @test_job_id = 'Perform TestJob every 5 seconds'
+    @test_job_log = 'All runs ok'
+    @test_job = Crono::CronoJob.create!(
+      job_id: @test_job_id,
+      log: @test_job_log
+    )
+  end
+
+  after { @test_job.destroy }
+
+  describe '/' do
+    it 'should show all jobs' do
+      get '/'
+      expect(last_response).to be_ok
+      expect(last_response.body).to include @test_job_id
+    end
+
+    it 'should show a error mark when a job is unhealthy' do
+      @test_job.update(healthy: false)
+      get '/'
+      expect(last_response.body).to include 'Error'
+    end
+  end
+
+  describe '/job/:id' do
+    it 'should show job log' do
+      get "/job/#{@test_job.id}"
+      expect(last_response).to be_ok
+      expect(last_response.body).to include @test_job_id
+      expect(last_response.body).to include @test_job_log
+    end
+
+    it 'should show a message about the unhealthy job' do
+      message = 'An error occurs during the last execution of this job'
+      @test_job.update(healthy: false)
+      get "/job/#{@test_job.id}"
+      expect(last_response.body).to include message
+    end
+  end
+end

web/views/dashboard.haml

@@ -7,11 +7,16 @@
     %th Job
     %th Last performed at
     %th
-  - for job in @jobs
+    %th
+  - @jobs.each do |job|
     %tr
       %td= job.job_id
-      %td= job.last_performed_at || "—"
+      %td= job.last_performed_at || '-'
       %td
-        %a{href: url("/jobs/#{job.id}")}
+        - if job.healthy == false
+          %a{ href: url("/job/#{job.id}") }
+            %span.label.label-danger Error
+      %td
+        %a{ href: url("/job/#{job.id}") }
           Log
           %span.glyphicon.glyphicon-menu-right

web/views/job.haml

@@ -1,8 +1,14 @@
 %ol.breadcrumb
   %li
-    %a{href: url("/")} Home
+    %a{ href: url('/') } Home
   %li.active= @job.job_id
 
 %h2
   "#{@job.job_id}" Log:
+
+- if @job.healthy == false
+  .alert.alert-danger{ role: 'alert' }
+    An error occurs during the last execution of this job.
+    Check the log below for details.
+
 %pre= @job.log

web/views/layout.haml

@@ -1,15 +1,15 @@
 !!! 5
-%html{lang: "en"}
+%html{ lang: 'en' }
   %head
-    %meta{charset: "utf-8"}
-    %meta{"http-equiv" => "X-UA-Compatible", content: "IE=edge"}
-    %meta{name: "viewport", content: "width=device-width, initial-scale=1"}
+    %meta{ charset: 'utf-8' }
+    %meta{ 'http-equiv' => 'X-UA-Compatible', content: 'IE=edge' }
+    %meta{ name: 'viewport', content: 'width=device-width, initial-scale=1' }
 
     %title Crono Dashboard
 
-    %link{href: "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css", rel: "stylesheet"}
-    %link{href: "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap-theme.min.css", rel: "stylesheet"}
-    %link{href: "#{env['SCRIPT_NAME']}/custom.css", rel: "stylesheet"}
+    %link{ href: 'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css', rel: 'stylesheet' }
+    %link{ href: 'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap-theme.min.css', rel: 'stylesheet' }
+    %link{ href: "#{env['SCRIPT_NAME']}/custom.css", rel: 'stylesheet' }
 
   %body
     %br
@@ -21,5 +21,5 @@
           %small Dashboard
       = yield
 
-    %script{src: "https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"}
-    %script{src: "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"}
+    %script{ src: 'https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js' }
+    %script{ src: 'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js' }