1 files changed, 75 insertions, 0 deletions
diff --git a/lib/chef/resource/helpers/cron_validations.rb b/lib/chef/resource/helpers/cron_validations.rb
new file mode 100644
index 0000000000..d09113d64c
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+++ b/lib/chef/resource/helpers/cron_validations.rb
@@ -0,0 +1,75 @@
+#
+# Copyright:: Copyright 2020, Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+class Chef
+  module ResourceHelpers
+    # a collection of methods for validating cron times. Used in the various cron-like resources
+    module CronValidations
+      # validate a provided value is between two other provided values
+      # we also allow * as a valid input
+      # @param spec the value to validate
+      # @param min the lowest value allowed
+      # @param max the highest value allowed
+      # @return [Boolean] valid or not?
+      def self.validate_numeric(spec, min, max)
+        return true if spec == "*"
+
+        if spec.respond_to? :to_int
+          return spec >= min && spec <= max
+        end
+
+        # Lists of invidual values, ranges, and step values all share the validity range for type
+        spec.split(%r{\/|-|,}).each do |x|
+          next if x == "*"
+          return false unless x =~ /^\d+$/
+
+          x = x.to_i
+          return false unless x >= min && x <= max
+        end
+        true
+      end
+
+      # validate the provided month value to be jan - dec, 1 - 12, or *
+      # @param spec the value to validate
+      # @return [Boolean] valid or not?
+      def self.validate_month(spec)
+        return true if spec == "*"
+
+        if spec.respond_to? :to_int
+          validate_numeric(spec, 1, 12)
+        elsif spec.respond_to? :to_str
+          # Named abbreviations are permitted but not as part of a range or with stepping
+          return true if %w{jan feb mar apr may jun jul aug sep oct nov dec}.include? spec.downcase
+
+          # 1-12 are legal for months
+          validate_numeric(spec, 1, 12)
+        else
+          false
+        end
+      end
+
+      # validate the provided day of the week is sun-sat, 0-7, or *
+      # @param spec the value to validate
+      # @return [Boolean] valid or not?
+      def self.validate_dow(spec)
+        spec == "*" ||
+          validate_numeric(spec, 0, 7) ||
+          %w{sun mon tue wed thu fri sat}.include?(String(spec).downcase)
+      end
+    end
+  end
+end