Raise errors for invalid combinations of interval

Reject illogical combinations of rule types with intervals that would never
align with any occurrences.

Author: avit

lib/ice_cube/rules/daily_rule.rb

@@ -11,6 +11,26 @@ def initialize(interval = 1)
       reset
     end
 
+    def verify_alignment(value, freq, rule_part)
+      return unless freq == :wday || freq == :day
+      return unless @validations[:interval]
+
+      interval_validation = @validations[:interval].first
+      interval_value = (rule_part == :interval) ? value : interval_validation.interval
+      return if interval_value == 1
+
+      if freq == :wday
+        return if (interval_value % 7).zero?
+        return if Array(@validations[:day]).empty?
+        message = "day can only be used with multiples of interval(7)"
+      else
+        (fixed_validation = other_fixed_value_validations.first) or return
+        message = "#{fixed_validation.key} can only be used with interval(1)"
+      end
+
+      yield ArgumentError.new(message)
+    end
+
   end
 
 end

lib/ice_cube/rules/monthly_rule.rb

@@ -11,6 +11,19 @@ def initialize(interval = 1)
       reset
     end
 
+    def verify_alignment(value, freq, rule_part)
+      return unless freq == :month
+      return unless @validations[:interval]
+
+      interval_validation = @validations[:interval].first
+      interval_value = (rule_part == :interval) ? value : interval_validation.interval
+      return if interval_value == 1 || (interval_value % 12).zero?
+      return if other_fixed_value_validations.empty?
+
+      message = "month_of_year can only be used with interval(1) or multiples of interval(12)"
+      yield ArgumentError.new(message)
+    end
+
   end
 
 end

lib/ice_cube/validated_rule.rb

@@ -51,6 +51,14 @@ def other_interval_validations
       Array(@validations[base_interval_validation.type])
     end
 
+    def other_fixed_value_validations
+      @validations.values.flatten.select { |v|
+        interval_type = (v.type == :wday ? :day : v.type)
+        v.class < Validations::FixedValue &&
+          interval_type == base_interval_validation.type
+      }
+    end
+
     # Compute the next time after (or including) the specified time in respect
     # to the given start time
     def next_time(time, start_time, closing_time)
@@ -185,6 +193,29 @@ def validation_names
       VALIDATION_ORDER & @validations.keys
     end
 
+    def verify_alignment(value, freq, rule_part, options={})
+      @validations[:interval] or return
+      interval_validation = @validations[:interval].first
+      interval_validation.type == freq or return
+      fixed_validations = other_fixed_value_validations
+      (last_validation = fixed_validations.min_by(&:value)) or return
+
+      alignment = (value - last_validation.value) % interval_validation.interval
+      return if alignment.zero?
+
+      validation_values = fixed_validations.map(&:value).join(', ')
+      if rule_part == :interval
+        message = "interval(#{value}) " \
+                  "must be a multiple of " \
+                  "intervals in #{last_validation.key}(#{validation_values})"
+      else
+        message = "intervals in #{last_validation.key}(#{validation_values}, #{value}) " \
+                  "must be multiples of " \
+                  "interval(#{interval_validation.interval})"
+      end
+      yield ArgumentError.new(message)
+    end
+
   end
 
 end

lib/ice_cube/validations/daily_interval.rb

@@ -4,7 +4,11 @@ module Validations::DailyInterval
 
     # Add a new interval validation
     def interval(interval)
-      @interval = normalized_interval(interval)
+      interval = normalized_interval(interval)
+      verify_alignment(interval, :wday, :interval) { |error| raise error }
+      verify_alignment(interval, :day, :interval)  { |error| raise error }
+
+      @interval = interval
       replace_validations_for(:interval, [Validation.new(@interval)])
       clobber_base_validations(:wday, :day)
       self

lib/ice_cube/validations/day.rb

@@ -10,6 +10,8 @@ def day(*days)
           raise ArgumentError, "expecting Integer or Symbol value for day, got #{day.inspect}"
         end
         day = TimeUtil.sym_to_wday(day)
+        verify_alignment(day, :wday, :day) { |error| raise error }
+
         validations_for(:day) << Validation.new(day)
       end
       clobber_base_validations(:wday, :day)
@@ -25,6 +27,10 @@ def initialize(day)
         @day = day
       end
 
+      def key
+        :day
+      end
+
       def type
         :wday
       end

lib/ice_cube/validations/day_of_month.rb

@@ -7,6 +7,7 @@ def day_of_month(*days)
         unless day.is_a?(Integer)
           raise ArgumentError, "expecting Integer value for day, got #{day.inspect}"
         end
+        verify_alignment(day, :day, :day_of_month) { |error| raise error }
         validations_for(:day_of_month) << Validation.new(day)
       end
       clobber_base_validations(:day, :wday)
@@ -22,6 +23,10 @@ def initialize(day)
         @day = day
       end
 
+      def key
+        :day_of_month
+      end
+
       def type
         :day
       end

lib/ice_cube/validations/hour_of_day.rb

@@ -8,6 +8,9 @@ def hour_of_day(*hours)
         unless hour.is_a?(Integer)
           raise ArgumentError, "expecting Integer value for hour, got #{hour.inspect}"
         end
+
+        verify_alignment(hour, :hour, :hour_of_day) { |error| raise error }
+
         validations_for(:hour_of_day) << Validation.new(hour)
       end
       clobber_base_validations(:hour)
@@ -23,6 +26,10 @@ def initialize(hour)
         @hour = hour
       end
 
+      def key
+        :hour_of_day
+      end
+
       def type
         :hour
       end

lib/ice_cube/validations/hourly_interval.rb

@@ -3,6 +3,8 @@ module IceCube
   module Validations::HourlyInterval
 
     def interval(interval)
+      verify_alignment(interval, :hour, :interval) { |error| raise error }
+
       @interval = normalized_interval(interval)
       replace_validations_for(:interval, [Validation.new(@interval)])
       clobber_base_validations(:hour)

lib/ice_cube/validations/minute_of_hour.rb

@@ -7,6 +7,9 @@ def minute_of_hour(*minutes)
         unless minute.is_a?(Integer)
           raise ArgumentError, "expecting Integer value for minute, got #{minute.inspect}"
         end
+
+        verify_alignment(minute, :min, :minute_of_hour) { |error| raise error }
+
         validations_for(:minute_of_hour) << Validation.new(minute)
       end
       clobber_base_validations(:min)
@@ -22,6 +25,10 @@ def initialize(minute)
         @minute = minute
       end
 
+      def key
+        :minute_of_hour
+      end
+
       def type
         :min
       end

lib/ice_cube/validations/minutely_interval.rb

@@ -3,6 +3,8 @@ module IceCube
   module Validations::MinutelyInterval
 
     def interval(interval)
+      verify_alignment(interval, :min, :interval) { |error| raise error }
+
       @interval = normalized_interval(interval)
       replace_validations_for(:interval, [Validation.new(@interval)])
       clobber_base_validations(:min)