Allow literal days of week and months in raw cron syntax

Last two fields of cron syntax allow days of week and months to be
entered as string literals instead of numbers.

Make the cron regex a little more strict so it won't match single words
like 'SUN' or 'Jan' as cron and allow the list of month and day
names as found in vixie cron.

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 * Allow setting the path within which Capistrano will execute whenever. [Samuel Johnson](https://github.com/javan/whenever/pull/619)
 
+* Allow the use of string literals for month and day-of-week in raw cron syntax.. [Potamianos Gregory](https://github.com/javan/whenever/pull/711)
+
 ### 0.9.7 / June 14, 2016
 
 * Restore compatibility with Capistrano v3; it has a bug which we have to work around [Ben Langfeld, Chris Gunther, Shohei Yamasaki]

lib/whenever/cron.rb

@@ -3,8 +3,10 @@
 module Whenever
   module Output
     class Cron
+      DAYS = %w(sun mon tue wed thu fri sat)
+      MONTHS = %w(jan feb mar apr may jun jul aug sep oct nov dec)
       KEYWORDS = [:reboot, :yearly, :annually, :monthly, :weekly, :daily, :midnight, :hourly]
-      REGEX = /^(@(#{KEYWORDS.join '|'})|((\*?[\d\/,\-]*)\s*){5})$/
+      REGEX = /^(@(#{KEYWORDS.join '|'})|((\*?[\d\/,\-]*)\s){3}(\*?([\d\/,\-]|(#{MONTHS.join '|'}))*\s)(\*?([\d\/,\-]|(#{DAYS.join '|'}))*))$/i
 
       attr_accessor :time, :task
 
@@ -56,8 +58,7 @@ def time_in_cron_syntax
 
     protected
       def day_given?
-        months = %w(jan feb mar apr may jun jul aug sep oct nov dec)
-        @at_given.is_a?(String) && (months.any? { |m| @at_given.downcase.index(m) } || @at_given[/\d\/\d/])
+        @at_given.is_a?(String) && (MONTHS.any? { |m| @at_given.downcase.index(m) } || @at_given[/\d\/\d/])
       end
 
       def parse_symbol
@@ -146,7 +147,7 @@ def parse_as_string
         return (timing << '1-5') * " " if string.downcase.index('weekday')
         return (timing << '6,0') * " " if string.downcase.index('weekend')
 
-        %w(sun mon tue wed thu fri sat).each_with_index do |day, i|
+        DAYS.each_with_index do |day, i|
           return (timing << i) * " " if string.downcase.index(day)
         end
 

test/unit/cron_test.rb

@@ -360,6 +360,7 @@ class CronParseRawTest < Whenever::TestCase
   should "return the same cron sytax" do
     crons = ['0 0 27-31 * *', '* * * * *', '2/3 1,9,22 11-26 1-6 *', '*/5 6-23 * * *',
              "*\t*\t*\t*\t*",
+             '7 17 * * FRI', '7 17 * * Mon-Fri', '30 12 * Jun *', '30 12 * Jun-Aug *',
              '@reboot', '@yearly', '@annually', '@monthly', '@weekly',
              '@daily', '@midnight', '@hourly']
     crons.each do |cron|