validate entities after creation if a validator is defined

lib/diaspora_federation/entity.rb

@@ -53,7 +53,9 @@ module DiasporaFederation
       self.class.default_values.merge(data).each do |k, v|
         instance_variable_set("@#{k}", nilify(v)) if setable?(k, v)
       end
+
       freeze
+      validate
     end
 
     # Returns a Hash representing this Entity (attributes => values)
@@ -115,6 +117,22 @@ module DiasporaFederation
       value
     end
 
+    def validate
+      validator_name = "DiasporaFederation::Validators::#{self.class.name.split('::').last}Validator"
+      return unless Validators.const_defined? validator_name
+
+      validator_class = Validators.const_get validator_name
+      validator = validator_class.new self
+      raise ValidationError, error_message(validator) unless validator.valid?
+    end
+
+    def error_message(validator)
+      errors = validator.errors.map do |prop, rule|
+        "property: #{prop}, value: #{public_send(prop).inspect}, rule: #{rule[:rule]}, with params: #{rule[:params]}"
+      end
+      "Failed validation for properties: #{errors.join(' | ')}"
+    end
+
     # Serialize the Entity into XML elements
     # @return [Nokogiri::XML::Element] root node
     def entity_xml
@@ -146,5 +164,9 @@ module DiasporaFederation
         node.content = data unless data.empty?
       end
     end
+
+    # Raised, if entity is not valid
+    class ValidationError < RuntimeError
+    end
   end
 end

lib/diaspora_federation/validators/rules/boolean.rb

@@ -2,7 +2,7 @@ module Validation
   module Rule
     class Boolean
       def error_key
-        :numeric
+        :boolean
       end
 
       def valid_value?(value)

spec/entities.rb

@@ -26,4 +26,14 @@ module DiasporaFederation
       property :qwer, xml_name: :asdf
     end
   end
+
+  module Validators
+    class TestDefaultEntityValidator < Validation::Validator
+      include Validation
+
+      rule :test1, regular_expression: {regex: /\A[^;]{,32}\z/}
+      rule :test2, :not_nil
+      rule :test3, :boolean
+    end
+  end
 end

spec/lib/diaspora_federation/entity_spec.rb

@@ -18,13 +18,14 @@ module DiasporaFederation
         }.to raise_error ArgumentError, "missing required properties: test1, test2"
       end
 
+      context "defaults" do
         it "sets the defaults" do
-        entity = Entities::TestDefaultEntity.new(test1: 1, test2: 2)
+          entity = Entities::TestDefaultEntity.new(test1: "1", test2: "2")
           expect(entity.test3).to be_truthy
         end
 
         it "handles callable defaults" do
-        entity = Entities::TestDefaultEntity.new(test1: 1, test2: 2)
+          entity = Entities::TestDefaultEntity.new(test1: "1", test2: "2")
           expect(entity.test4).to be_truthy
         end
 
@@ -33,12 +34,35 @@ module DiasporaFederation
           expect(entity.test3).to be_falsey
           expect(entity.test4).to be_falsey
         end
+      end
 
       it "sets nil if string is empty" do
         data[:test1] = ""
         entity = Entities::TestDefaultEntity.new(data)
         expect(entity.test1).to be_nil
       end
+
+      context "validation" do
+        let(:invalid_data) { {test1: "as;df", test2: nil, test3: "no boolean"} }
+
+        it "validates the entity and raise an error with failed properties if not valid" do
+          expect {
+            Entities::TestDefaultEntity.new(invalid_data)
+          }.to raise_error Entity::ValidationError, /Failed validation for properties:.*test1.*\|.*test2.*\|.*test3/
+        end
+
+        it "contains the failed rule" do
+          expect {
+            Entities::TestDefaultEntity.new(invalid_data)
+          }.to raise_error Entity::ValidationError, /property: test2, value: nil, rule: not_nil, with params: \{\}/
+        end
+
+        it "contains the params of the failed rule" do
+          expect {
+            Entities::TestDefaultEntity.new(invalid_data)
+          }.to raise_error Entity::ValidationError, /rule: regular_expression, with params: \{:regex=>.*\}/
+        end
+      end
     end
 
     describe "#to_h" do