lib/nanoc/base/contracts_support.rb in nanoc-4.4.4 vs lib/nanoc/base/contracts_support.rb in nanoc-4.4.5

@@ -27,29 +27,82 @@
       None        = Ignorer.instance
       ArrayOf     = Ignorer.instance
       Or          = Ignorer.instance
       Func        = Ignorer.instance
       RespondTo   = Ignorer.instance
+      Named       = Ignorer.instance
+      IterOf      = Ignorer.instance
+      HashOf      = Ignorer.instance
 
       def contract(*args); end
     end
 
     module EnabledContracts
+      class AbstractContract
+        def self.[](*vals)
+          new(*vals)
+        end
+      end
+
+      class Named < AbstractContract
+        def initialize(name)
+          @name = name
+        end
+
+        def valid?(val)
+          val.is_a?(Kernel.const_get(@name))
+        end
+
+        def inspect
+          "#{self.class}(#{@name})"
+        end
+      end
+
+      class IterOf < AbstractContract
+        def initialize(contract)
+          @contract = contract
+        end
+
+        def valid?(val)
+          val.respond_to?(:each) && val.all? { |v| Contract.valid?(v, @contract) }
+        end
+
+        def inspect
+          "#{self.class}(#{@contract})"
+        end
+      end
+
       def contract(*args)
         Contract(*args)
       end
     end
 
-    def self.included(base)
+    def self.setup_once
+      @_contracts_support__setup ||= false
+      return @_contracts_support__should_enable if @_contracts_support__setup
+      @_contracts_support__setup = true
+
       contracts_loadable =
         begin
           require 'contracts'
           true
         rescue LoadError
           false
         end
 
-      should_enable = contracts_loadable && !ENV.key?('DISABLE_CONTRACTS')
+      @_contracts_support__should_enable = contracts_loadable && !ENV.key?('DISABLE_CONTRACTS')
+
+      if @_contracts_support__should_enable
+        # FIXME: ugly
+        ::Contracts.const_set('Named', EnabledContracts::Named)
+        ::Contracts.const_set('IterOf', EnabledContracts::IterOf)
+      end
+
+      @_contracts_support__should_enable
+    end
+
+    def self.included(base)
+      should_enable = setup_once
 
       if should_enable
         unless base.include?(::Contracts::Core)
           base.include(::Contracts::Core)
           base.extend(EnabledContracts)