lib/plumbing/chain.rb in standard-procedure-plumbing-0.1.2 vs lib/plumbing/chain.rb in standard-procedure-plumbing-0.2.0

@@ -1,59 +1,14 @@
+require_relative "chain/contracts"
+require_relative "chain/operations"
+
 module Plumbing
   # A chain of operations that are executed in sequence
   class Chain
-    def call params
-      self.class._call params, self
-    end
+    extend Plumbing::Chain::Contracts
+    extend Plumbing::Chain::Operations
 
-    class << self
-      def pre_condition name, &validator
-        pre_conditions[name.to_sym] = validator
-      end
-
-      def perform method, &implementation
-        implementation ||= ->(params, instance) { instance.send(method, params) }
-        operations << implementation
-      end
-
-      def post_condition name, &validator
-        post_conditions[name.to_sym] = validator
-      end
-
-      def _call params, instance
-        validate_preconditions_for params
-        result = params
-        operations.each do |operation|
-          result = operation.call(result, instance)
-        end
-        validate_postconditions_for result
-        result
-      end
-
-      private
-
-      def operations
-        @operations ||= []
-      end
-
-      def pre_conditions
-        @pre_conditions ||= {}
-      end
-
-      def post_conditions
-        @post_conditions ||= {}
-      end
-
-      def validate_preconditions_for input
-        failed_preconditions = pre_conditions.select { |name, validator| !validator.call(input) }
-        raise PreConditionError, failed_preconditions.keys.join(", ") if failed_preconditions.any?
-        input
-      end
-
-      def validate_postconditions_for output
-        failed_postconditions = post_conditions.select { |name, validator| !validator.call(output) }
-        raise PostConditionError, failed_postconditions.keys.join(", ") if failed_postconditions.any?
-        output
-      end
+    def call input
+      self.class._call input, self
     end
   end
 end