Perform bnode renaming before creating the node map to handle embedded nodes. Adds test option to do result comparison by remapping bnode labels based on dataset bijection.

Author: gkellogg

lib/json/ld/api.rb

@@ -278,7 +278,7 @@ def self.flatten(input, context, expanded: false, **options)
         log_debug(".flatten") {"expanded input: #{value.to_json(JSON_STATE) rescue 'malformed json'}"}
 
         # Rename blank nodes recusively. Note that this does not create new blank node identifiers where none exist, which is performed in the node map generation algorithm.
-        #@value = rename_bnodes(@value) if @options[:rename_bnodes]
+        @value = rename_bnodes(@value) if @options[:rename_bnodes]
 
         # Initialize node map to a JSON object consisting of a single member whose key is @default and whose value is an empty JSON object.
         graph_maps = {'@default' => {}}
@@ -400,6 +400,9 @@ def self.frame(input, frame, expanded: false, **options)
           options[:omitGraph] = context.processingMode('json-ld-1.1')
         end
 
+        # Rename blank nodes recusively. Note that this does not create new blank node identifiers where none exist, which is performed in the node map generation algorithm.
+        @value = rename_bnodes(@value)
+
         # Get framing nodes from expanded input, replacing Blank Node identifiers as necessary
         create_node_map(value, framing_state[:graphMap], active_graph: '@default')
 

lib/json/ld/flatten.rb

@@ -99,12 +99,10 @@ def create_node_map(element, graph_map,
           # Element is a node object
           ser_id = id = element.delete('@id')
           if id.is_a?(Hash)
-            # recursively rename blank nodes within `id`.
-            id = rename_embedded(id)
             # Index graph using serialized id
             ser_id = id.to_json_c14n
-          elsif blank_node?(id)
-            ser_id = id = namer.get_name(id)
+          elsif id.nil?
+            ser_id = id = namer.get_name
           end
 
           node = graph[ser_id] ||= {'@id' => id}
@@ -198,14 +196,14 @@ def create_node_map(element, graph_map,
     #
     # @param [Object] node
     # @return [Hash]
-    def rename_embedded(node)
+    def rename_bnodes(node)
       case node
       when String
         blank_node?(node) ? namer.get_name(node) : node
       when Array
-        node.map {|n| rename_embedded(n)}
+        node.map {|n| rename_bnodes(n)}
       when Hash
-        node.inject({}) {|memo, (k, v)| memo.merge(k => rename_embedded(v))}
+        node.inject({}) {|memo, (k, v)| memo.merge(k => rename_bnodes(v))}
       else
         node
       end

spec/flatten_spec.rb

@@ -206,7 +206,8 @@
               "http://example.org/bar": [ { "@id": "_:b0" } ]
             }
           ]
-        }
+        },
+        remap_nodes: true
       },
       "@list with embedded object": {
         input: %([{
@@ -1195,6 +1196,8 @@ def run_flatten(params)
       else
         expect{jld = JSON::LD::API.flatten(input, context, logger: logger, **params)}.not_to write.to(:error)
       end
+
+      jld = remap_bnodes(jld, output) if params[:remap_nodes]
       expect(jld).to produce_jsonld(output, logger)
     end
   end

spec/spec_helper.rb

@@ -67,6 +67,39 @@ def detect_format(stream)
   end
 end
 
+# Creates a bijection between the two objects and replaces nodes in actual from expected.
+def remap_bnodes(actual, expected)
+  # Transform each to RDF and perform a blank node bijection.
+  # Replace the blank nodes in action with the mapping from bijection.
+  ds_actual = RDF::Repository.new << JSON::LD::API.toRdf(actual, rdfstar: true, rename_bnodes: false)
+  ds_expected = RDF::Repository.new << JSON::LD::API.toRdf(expected, rdfstar: true, rename_bnodes: false)
+  if bijection = ds_actual.bijection_to(ds_expected)
+    bijection = bijection.inject({}) {|memo, (k, v)| memo.merge(k.to_s => v.to_s)}
+
+    # Recursively replace blank nodes in actual with the bijection
+    #require 'byebug'; byebug
+    replace_nodes(actual, bijection)
+  else
+    actual
+  end
+end
+
+def replace_nodes(object, bijection)
+  case object
+  when Array
+    object.map {|o| replace_nodes(o, bijection)}
+  when Hash
+    object.inject({}) do |memo, (k, v)|
+      memo.merge(bijection.fetch(k, k) => replace_nodes(v, bijection))
+    end
+  when String
+    bijection.fetch(object, object)
+  else
+    object
+  end
+end
+
+
 LIBRARY_INPUT = JSON.parse(%([
   {
     "@id": "http://example.org/library",

spec/suite_flatten_spec.rb

@@ -7,6 +7,8 @@
     m = Fixtures::SuiteTest::Manifest.open("#{Fixtures::SuiteTest::SUITE}flatten-manifest.jsonld")
     describe m.name do
       m.entries.each do |t|
+        t.options[:remap_bnodes] = %w(#t0045).include?(t.property('@id'))
+
         specify "#{t.property('@id')}: #{t.name} unordered#{' (negative test)' unless t.positiveTest?}" do
           t.options[:ordered] = false
           if %w(#t0005).include?(t.property('@id'))
@@ -16,6 +18,8 @@
           end
         end
 
+        # Skip ordered tests when remapping bnodes
+        next if t.options[:remap_bnodes]
         specify "#{t.property('@id')}: #{t.name} ordered#{' (negative test)' unless t.positiveTest?}" do
           t.options[:ordered] = true
           if %w(#t0005).include?(t.property('@id'))

spec/suite_frame_spec.rb

@@ -7,13 +7,23 @@
     m = Fixtures::SuiteTest::Manifest.open("#{Fixtures::SuiteTest::FRAME_SUITE}frame-manifest.jsonld")
     describe m.name do
       m.entries.each do |t|
+        t.options[:remap_bnodes] = %w(#t0021 #tp021).include?(t.property('@id'))
+
         specify "#{t.property('@id')}: #{t.name} unordered#{' (negative test)' unless t.positiveTest?}" do
           t.options[:ordered] = false
+          if %w(#t0021 #tp021).include?(t.property('@id'))
+            pending("changes due to blank node reordering")
+          end
           expect {t.run self}.not_to write.to(:error)
         end
 
+        # Skip ordered tests when remapping bnodes
+        next if t.options[:remap_bnodes]
         specify "#{t.property('@id')}: #{t.name} ordered#{' (negative test)' unless t.positiveTest?}" do
           t.options[:ordered] = true
+          if %w(#t0021 #tp021).include?(t.property('@id'))
+            pending("changes due to blank node reordering")
+          end
           expect {t.run self}.not_to write.to(:error)
         end
       end

spec/suite_helper.rb

@@ -264,6 +264,10 @@ def run(rspec_example = nil)
                 }
               else
                 expected = JSON.load(expect)
+
+                # If called for, remap bnodes
+                result = remap_bnodes(result, expected) if options[:remap_bnodes]
+
                 if options[:ordered]
                   # Compare without transformation
                   rspec_example.instance_eval {