Render graph to file and png

lib/mosaik/commands/extract.rb

@@ -49,6 +49,12 @@ def call
           .new(options, graph)
           .tap(&:validate)
           .call
+
+        # Write graph to file
+        debug graph.to_dot
+        graph.to_png("mosaik")
+
+        info "Graph written to mosaik.dot and rendered to mosaik.png"
       end
 
       private

lib/mosaik/graph/edge.rb

@@ -12,6 +12,10 @@ def initialize(attributes = {})
         @attributes = attributes
       end
 
+      def to_dot
+        attributes.map { |k, v| "#{k}=#{v}" }.join(", ")
+      end
+
       def inspect
         "#<#{self.class.name} attributes=#{attributes.map { |k, v| "#{k}: #{v}" }.join(',')}>"
       end

lib/mosaik/graph/graph.rb

@@ -62,6 +62,19 @@ def tsort_each_child(vertex, &)
         end
       end
 
+      def to_dot
+        <<~DOT
+          digraph {
+            #{vertices.values.map(&:to_dot).join("\n  ")}
+          }
+        DOT
+      end
+
+      def to_png(file)
+        File.write("#{file}.dot", to_dot)
+        system("dot -Tpng #{file}.dot -o #{file}.png")
+      end
+
       def inspect
         "#<#{self.class.name} vertices=#{vertices.values.map(&:inspect)}>"
       end

lib/mosaik/graph/vertex.rb

@@ -22,6 +22,14 @@ def remove_edge(id)
         edges.delete(id)
       end
 
+      def to_dot
+        edges.map do |to, edges|
+          edges.map do |edge|
+            "\"#{id}\" -> \"#{to}\" [#{edge.to_dot}]"
+          end
+        end.flatten.join("\n  ")
+      end
+
       def inspect
         "#<#{self.class.name} id=#{id} attributes=#{attributes.map { |k, v| "#{k}: #{v}" }.join(',')} edges=#{edges.count}>"
       end