add alias functionality to entities

* add diaspora_id alias to Person and Profile for Discovery
* also diaspora_id for AccountDeletion

lib/diaspora_federation/entities/account_deletion.rb

@@ -8,7 +8,11 @@ module DiasporaFederation
       #   The diaspora ID of the deleted account
       #   @see Person#author
       #   @return [String] diaspora ID
-      property :author, xml_name: :diaspora_handle
+      # @!attribute [r] diaspora_id
+      #   Alias for author
+      #   @see AccountDeletion#author
+      #   @return [String] diaspora ID
+      property :author, alias: :diaspora_id, xml_name: :diaspora_handle
     end
   end
 end

lib/diaspora_federation/entities/person.rb

@@ -15,7 +15,11 @@ module DiasporaFederation
       #   The diaspora ID of the person
       #   @see Validation::Rule::DiasporaId
       #   @return [String] diaspora ID
-      property :author, xml_name: :diaspora_handle
+      # @!attribute [r] diaspora_id
+      #   Alias for author
+      #   @see Person#author
+      #   @return [String] diaspora ID
+      property :author, alias: :diaspora_id, xml_name: :diaspora_handle
 
       # @!attribute [r] url
       #   @see Discovery::WebFinger#seed_url

lib/diaspora_federation/entities/profile.rb

@@ -8,7 +8,11 @@ module DiasporaFederation
       #   The diaspora ID of the person
       #   @see Person#author
       #   @return [String] diaspora ID
-      property :author, xml_name: :diaspora_handle
+      # @!attribute [r] diaspora_id
+      #   Alias for author
+      #   @see Profile#author
+      #   @return [String] diaspora ID
+      property :author, alias: :diaspora_id, xml_name: :diaspora_handle
 
       # @!attribute [r] first_name
       #   @deprecated We decided to only use one name field, these should be removed

lib/diaspora_federation/entity.rb

@@ -56,15 +56,16 @@ module DiasporaFederation
     # @return [Entity] new instance
     def initialize(data, additional_xml_elements=nil)
       raise ArgumentError, "expected a Hash" unless data.is_a?(Hash)
-      missing_props = self.class.missing_props(data)
+      entity_data = self.class.resolv_aliases(data)
+      missing_props = self.class.missing_props(entity_data)
       unless missing_props.empty?
         raise ArgumentError, "missing required properties: #{missing_props.join(', ')}"
       end
 
       @additional_xml_elements = nilify(additional_xml_elements)
 
-      self.class.default_values.merge(data).each do |k, v|
+      self.class.default_values.merge(entity_data).each do |name, value|
-        instance_variable_set("@#{k}", nilify(v)) if setable?(k, v)
+        instance_variable_set("@#{name}", nilify(value)) if setable?(name, value)
       end
 
       freeze

lib/diaspora_federation/properties_dsl.rb

@@ -7,6 +7,7 @@ module DiasporaFederation
   #   property :optional, default: false
   #   property :dynamic_default, default: -> { Time.now }
   #   property :another_prop, xml_name: :another_name
+  #   property :original_prop, alias: :alias_prop
   #   entity :nested, NestedEntity
   #   entity :multiple, [OtherEntity]
   module PropertiesDSL
@@ -66,6 +67,20 @@ module DiasporaFederation
       @class_prop_names ||= class_props.map {|p| p[:name] }
     end
 
+    # @param [Hash] data entity data
+    # @return [Hash] hash with resolved aliases
+    def resolv_aliases(data)
+      Hash[data.map {|name, value|
+        if class_prop_aliases.has_key? name
+          prop_name = class_prop_aliases[name]
+          raise InvalidData, "only use '#{name}' OR '#{prop_name}'" if data.has_key? prop_name
+          [prop_name, value]
+        else
+          [name, value]
+        end
+      }]
+    end
+
     # finds a property by +xml_name+ or +name+
     # @param [String] xml_name name of the property from the received xml
     # @return [Hash] the property data
@@ -99,6 +114,8 @@ module DiasporaFederation
       default_props[name] = opts[:default] if opts.has_key? :default
 
       instance_eval { attr_reader name }
+
+      define_alias(name, opts[:alias]) if opts.has_key? :alias
     end
 
     # checks if the name is a +Symbol+ or a +String+
@@ -121,6 +138,19 @@ module DiasporaFederation
       @default_props ||= {}
     end
 
+    # Returns all alias mappings
+    # @return [Hash] alias properties
+    def class_prop_aliases
+      @class_prop_aliases ||= {}
+    end
+
+    # @param [Symbol] name property name
+    # @param [Symbol] alias_name alias name
+    def define_alias(name, alias_name)
+      class_prop_aliases[alias_name] = name
+      instance_eval { alias_method alias_name, name }
+    end
+
     # Raised, if the name is of an unexpected type
     class InvalidName < RuntimeError
     end
@@ -128,5 +158,9 @@ module DiasporaFederation
     # Raised, if the type is of an unexpected type
     class InvalidType < RuntimeError
     end
+
+    # Raised, if the data contains property twice (with name AND alias)
+    class InvalidData < RuntimeError
+    end
   end
 end

spec/lib/diaspora_federation/properties_dsl_spec.rb

@@ -124,6 +124,35 @@ module DiasporaFederation
       end
     end
 
+    describe ".resolv_aliases" do
+      it "resolves the defined alias" do
+        dsl.property :test, alias: :test_alias
+        data = dsl.resolv_aliases(test_alias: "foo")
+        expect(data[:test]).to eq("foo")
+        expect(data).not_to have_key(:test_alias)
+      end
+
+      it "raises when alias and original property are present" do
+        dsl.property :test, alias: :test_alias
+        expect {
+          dsl.resolv_aliases(test_alias: "foo", test: "bar")
+        }.to raise_error PropertiesDSL::InvalidData, "only use 'test_alias' OR 'test'"
+      end
+
+      it "returns original data if no alias is defined" do
+        dsl.property :test, alias: :test_alias
+        data = dsl.resolv_aliases(test: "foo")
+        expect(data[:test]).to eq("foo")
+      end
+
+      it "returns original data if alias is defined, but not present" do
+        dsl.property :test
+        data = dsl.resolv_aliases(test: "foo")
+        expect(data[:test]).to eq("foo")
+        expect(data).not_to have_key(:test_alias)
+      end
+    end
+
     describe ".find_property_for_xml_name" do
       it "finds property by xml_name" do
         dsl.property :test, xml_name: :xml_test