Avoid all the Maybe nonsense (#2224)

Rename dep classes

Split into files

Sass was still returning nil

Let's make dependencies immutable

Avoid IsA

Fix contract

.gitignore

@@ -23,4 +23,5 @@ Makefile
 .idea
 *.sublime-workspace
 /bin
-/vendor/bundle/
+/vendor/bundle/
+deps.yml

middleman-core/lib/middleman-core/builder.rb

@@ -2,7 +2,9 @@ require 'pathname'
 require 'fileutils'
 require 'tempfile'
 require 'parallel'
-require 'middleman-core/dependencies'
+require 'middleman-core/dependencies/graph'
+require 'middleman-core/dependencies/edge'
+require 'middleman-core/dependencies/vertices/file_vertex'
 require 'middleman-core/callback_manager'
 require 'middleman-core/contracts'
 
@@ -81,8 +83,7 @@ module Middleman
         prerender_css.tap do |resources|
           if @track_dependencies
             resources.each do |r|
-              dependency = r[1]
-              @graph.add_dependency(dependency) unless dependency.nil?
+              @graph.add_edge(r[1]) unless r[1].nil?
             end
           end
         end
@@ -94,8 +95,7 @@ module Middleman
         output_files.tap do |resources|
           if @track_dependencies
             resources.each do |r|
-              dependency = r[1]
-              @graph.add_dependency(dependency) unless dependency.nil?
+              @graph.add_edge(r[1]) unless r[1].nil?
             end
           end
         end
@@ -120,7 +120,7 @@ module Middleman
 
     # Pre-request CSS to give Compass a chance to build sprites
     # @return [Array<Resource>] List of css resources that were output.
-    Contract ArrayOf[[Pathname, Maybe[::Middleman::Dependencies::DependencyLink]]]
+    Contract ArrayOf[[Pathname, Maybe[::Middleman::Dependencies::Edge]]]
     def prerender_css
       logger.debug '== Prerendering CSS'
 
@@ -143,7 +143,7 @@ module Middleman
 
     # Find all the files we need to output and do so.
     # @return [Array<Resource>] List of resources that were output.
-    Contract ArrayOf[[Pathname, Maybe[::Middleman::Dependencies::DependencyLink]]]
+    Contract ArrayOf[[Pathname, Maybe[::Middleman::Dependencies::Edge]]]
     def output_files
       logger.debug '== Building files'
 
@@ -155,7 +155,7 @@ module Middleman
       output_resources(resources.to_a)
     end
 
-    Contract OldResourceList => ArrayOf[Or[Bool, [Pathname, Maybe[::Middleman::Dependencies::DependencyLink]]]]
+    Contract OldResourceList => ArrayOf[Or[Bool, [Pathname, Maybe[::Middleman::Dependencies::Edge]]]]
     def output_resources(resources)
       res_count = resources.count
 
@@ -278,7 +278,7 @@ module Middleman
     # Try to output a resource and capture errors.
     # @param [Middleman::Sitemap::Resource] resource The resource.
     # @return [void]
-    Contract IsA['Middleman::Sitemap::Resource'] => Or[Bool, [Pathname, Maybe[::Middleman::Dependencies::DependencyLink]]]
+    Contract IsA['Middleman::Sitemap::Resource'] => Or[Bool, [Pathname, Maybe[::Middleman::Dependencies::Edge]]]
     def output_resource(resource)
       ::Middleman::Util.instrument 'builder.output.resource', path: File.basename(resource.destination_path) do
         begin
@@ -305,17 +305,17 @@ module Middleman
             end
           end
 
-          deps = nil
+          vertices = nil
 
           if resource.binary?
             export_file!(output_file, resource.file_descriptor[:full_path], true)
           else
             content = resource.render({}, {})
 
-            unless resource.dependencies.empty?
-              deps = ::Middleman::Dependencies::DependencyLink.new(
-                ::Middleman::Dependencies::FileDependency.from_resource(resource),
-                resource.dependencies
+            unless resource.vertices.empty?
+              vertices = ::Middleman::Dependencies::Edge.new(
+                ::Middleman::Dependencies::FileVertex.from_resource(resource),
+                resource.vertices
               )
             end
 
@@ -326,7 +326,7 @@ module Middleman
           return false
         end
 
-        [output_file, deps]
+        [output_file, vertices]
       end
     end
 

middleman-core/lib/middleman-core/contracts.rb

@@ -19,6 +19,29 @@ if ENV['CONTRACTS'] != 'false'
     end
 
     VectorOf = Contracts::CollectionOf::Factory.new(::Hamster::Vector)
+
+    class ImmutableHashOf < Contracts::CallableClass
+      INVALID_KEY_VALUE_PAIR = 'You should provide only one key-value pair to HashOf contract'.freeze
+
+      def initialize(key, value)
+        @key   = key
+        @value = value
+      end
+
+      def valid?(hash)
+        return false unless hash.is_a?(::Hamster::Hash)
+
+        keys_match = hash.keys.map { |k| Contract.valid?(k, @key) }.all?
+        vals_match = hash.values.map { |v| Contract.valid?(v, @value) }.all?
+
+        [keys_match, vals_match].all?
+      end
+
+      def to_s
+        "ImmutableHash<#{@key}, #{@value}>"
+      end
+    end
+
     ImmutableSetOf = Contracts::CollectionOf::Factory.new(::Hamster::Set)
     ImmutableSortedSetOf = Contracts::CollectionOf::Factory.new(::Hamster::SortedSet)
     OldResourceList = Contracts::ArrayOf[IsA['Middleman::Sitemap::Resource']]
@@ -110,6 +133,9 @@ else
     class VectorOf < Callable
     end
 
+    class ImmutableHashOf < Callable
+    end
+
     class ImmutableSetOf < Callable
     end
   end

middleman-core/lib/middleman-core/dependencies.rb

@@ -1,261 +1,47 @@
-require 'middleman-core/contracts'
 require 'set'
 require 'pathname'
+require 'digest/sha1'
 require 'yaml'
+require 'middleman-core/contracts'
+require 'middleman-core/dependencies/graph'
+require 'middleman-core/dependencies/vertices'
 
 module Middleman
   module Dependencies
-    class BaseDependency
-      include Contracts
-
-      DEPENDENCY_KEY = Or[String, Symbol]
-      DEPENDENCY_ATTRS = HashOf[Symbol, String]
-      SERIALIZED_DEPENDENCY = {
-        key: Any, # Weird inheritance bug
-        type: Symbol,
-        attributes: DEPENDENCY_ATTRS
-      }.freeze
-
-      Contract DEPENDENCY_KEY
-      attr_reader :key
-
-      Contract DEPENDENCY_ATTRS
-      attr_reader :attributes
-
-      Contract DEPENDENCY_KEY, DEPENDENCY_ATTRS => Any
-      def initialize(key, attributes)
-        @key = key
-        @attributes = attributes
-      end
-
-      Contract BaseDependency => Bool
-      def ==(other)
-        key == other.key
-      end
-
-      Contract Bool
-      def valid?
-        raise NotImplementedError
-      end
-
-      Contract IsA['Middleman::Sitemap::Resource'] => Bool
-      def invalidates_resource?(_resource)
-        raise NotImplementedError
-      end
-
-      Contract Maybe[DEPENDENCY_ATTRS] => SERIALIZED_DEPENDENCY
-      def serialize(attributes = {})
-        {
-          key: @key,
-          type: type_id,
-          attributes: @attributes.merge(attributes)
-        }
-      end
-
-      protected
-
-      Contract Symbol
-      def type_id
-        self.class.const_get :TYPE_ID
-      end
-
-      Contract Pathname, String => String
-      def relative_path(root, file)
-        Pathname(File.expand_path(file)).relative_path_from(root).to_s
-      end
-
-      Contract Pathname, String => String
-      def full_path(root, file)
-        File.expand_path(file, root)
-      end
-    end
-
-    class FileDependency < BaseDependency
-      include Contracts
-
-      TYPE_ID = :file
-
-      Contract IsA['::Middleman::Application'], String, BaseDependency::DEPENDENCY_ATTRS => FileDependency
-      def self.deserialize(app, key, attributes)
-        FileDependency.new(app.root_path, key, attributes)
-      end
-
-      Contract IsA['Middleman::Sitemap::Resource'] => FileDependency
-      def self.from_resource(resource)
-        from_source_file(resource.app, resource.file_descriptor)
-      end
-
-      Contract IsA['::Middleman::Application'], IsA['::Middleman::SourceFile'] => FileDependency
-      def self.from_source_file(app, source_file)
-        FileDependency.new(app.root_path, source_file[:full_path].to_s)
-      end
-
-      Contract Or[String, Pathname], String, Maybe[DEPENDENCY_ATTRS] => Any
-      def initialize(root, key, attributes = {})
-        @root = Pathname(root)
-        @full_path = full_path(@root, key)
-        super(relative_path(@root, key), attributes)
-      end
-
-      Contract Bool
-      def valid?
-        @is_valid = (previous_hash.nil? || hash_file == previous_hash) if @is_valid.nil?
-        @is_valid
-      end
-
-      Contract IsA['Middleman::Sitemap::Resource'] => Bool
-      def invalidates_resource?(resource)
-        resource.file_descriptor[:full_path].to_s == @full_path
-      end
-
-      Contract BaseDependency::SERIALIZED_DEPENDENCY
-      def serialize
-        super({
-          hash: valid? && !previous_hash.nil? ? previous_hash : hash_file
-        })
-      end
-
-      private
-
-      Contract Maybe[String]
-      def previous_hash
-        @attributes[:hash]
-      end
-
-      Contract String
-      def hash_file
-        ::Digest::SHA1.file(@full_path).hexdigest
-      end
-    end
-
-    DEPENDENCY_CLASSES_BY_TYPE = {
-      FileDependency::TYPE_ID => FileDependency
-    }.freeze
-
-    class DependencyLink
-      include Contracts
-
-      Contract BaseDependency
-      attr_reader :dependency
-
-      Contract Maybe[SetOf[BaseDependency]]
-      attr_accessor :depends_on
-
-      Contract BaseDependency, Maybe[SetOf[BaseDependency]] => Any
-      def initialize(dependency, depends_on = nil)
-        @dependency = dependency
-        @depends_on = nil
-        @depends_on = Set.new(depends_on) unless depends_on.nil?
-      end
-
-      Contract String
-      def to_s
-        "#<#{self.class} file=#{@dependency} depends_on=#{@depends_on}>"
-      end
-    end
-
-    class Graph
-      include Contracts
-
-      Contract HashOf[BaseDependency::DEPENDENCY_KEY, BaseDependency]
-      attr_reader :dependencies
-
-      Contract HashOf[BaseDependency, SetOf[BaseDependency]]
-      attr_accessor :dependency_map
-
-      def initialize(dependencies = {})
-        @dependencies = dependencies
-        @dependency_map = {}
-      end
-
-      Contract BaseDependency => BaseDependency
-      def known_dependency_or_new(dep)
-        @dependencies[dep.key] ||= dep
-      end
-
-      Contract DependencyLink => Any
-      def add_dependency(link)
-        deduped_depender = known_dependency_or_new link.dependency
-
-        @dependency_map[deduped_depender] ||= Set.new
-        @dependency_map[deduped_depender] << deduped_depender
-
-        return if link.depends_on.nil?
-
-        link.depends_on.each do |depended_on|
-          deduped_depended_on = known_dependency_or_new depended_on
-
-          @dependency_map[deduped_depended_on] ||= Set.new
-          @dependency_map[deduped_depended_on] << deduped_depended_on
-          @dependency_map[deduped_depended_on] << deduped_depender
-        end
-      end
-
-      Contract String => Bool
-      def exists?(file_path)
-        @dependency_map.key?(file_path)
-      end
-
-      Contract SetOf[BaseDependency]
-      def invalidated
-        @_invalidated_cache ||= begin
-          invalidated_dependencies = @dependency_map.keys.select do |dependency|
-            # Either "Missing from known dependencies"
-            # Or invalided by the class
-            !@dependencies.key?(dependency.key) || !dependency.valid?
-          end
-
-          invalidated_dependencies.reduce(Set.new) do |sum, dependency|
-            sum | invalidated_with_parents(dependency)
-          end
-        end
-      end
-
-      Contract BaseDependency => SetOf[BaseDependency]
-      def invalidated_with_parents(dependency)
-        # TODO, recurse more?
-        (Set.new + (@dependency_map[dependency])) << dependency
-      end
-
-      Contract IsA['::Middleman::Sitemap::Resource'] => Bool
-      def invalidates_resource?(resource)
-        invalidated.any? { |d| d.invalidates_resource?(resource) }
-      end
-    end
-
     include Contracts
 
+    DEFAULT_FILE_PATH = 'deps.yml'.freeze
+    RUBY_FILES = ['**/*.rb', 'Gemfile.lock'].freeze
+
     module_function
 
     Contract IsA['::Middleman::Application'], Graph => String
     def serialize(app, graph)
-      ruby_files = Dir['**/*.rb', 'Gemfile.lock'].reduce([]) do |sum, file|
+      ruby_files = Dir.glob(RUBY_FILES).reduce([]) do |sum, file|
         sum << {
           file: Pathname(File.expand_path(file)).relative_path_from(app.root_path).to_s,
           hash: ::Digest::SHA1.file(file).hexdigest
         }
       end
 
-      dependency_links = graph.dependency_map.reduce([]) do |sum, (dependency, depended_on_by)|
+      edges = graph.dependency_map.reduce([]) do |sum, (vertex, depended_on_by)|
         sum << {
-          key: dependency.key,
-          depended_on_by: depended_on_by.delete(dependency).to_a.map(&:key).sort
+          key: vertex.key,
+          depended_on_by: depended_on_by.delete(vertex).to_a.map(&:key).sort
         }
       end
 
-      dependencies = graph.dependency_map.reduce([]) do |sum, (dependency, _depended_on_by)|
-        sum << dependency.serialize
+      vertices = graph.dependency_map.reduce([]) do |sum, (vertex, _depended_on_by)|
+        sum << vertex.serialize
       end
 
       ::YAML.dump(
         ruby_files: ruby_files.sort_by { |d| d[:file] },
-        dependency_links: dependency_links.sort_by { |d| d[:file] },
-        dependencies: dependencies.sort_by { |d| d[:key] }
+        edges: edges.sort_by { |d| d[:file] },
+        vertices: vertices.sort_by { |d| d[:key] }
       )
     end
 
-    DEFAULT_FILE_PATH = 'deps.yml'.freeze
-
     Contract IsA['::Middleman::Application'], Graph, Maybe[String] => Any
     def serialize_and_save(app, graph, file_path = DEFAULT_FILE_PATH)
       File.open(file_path, 'w') do |file|
@@ -302,19 +88,19 @@ module Middleman
         raise InvalidatedRubyFiles, invalidated
       end
 
-      dependencies = data[:dependencies].each_with_object({}) do |row, sum|
-        dep_class = DEPENDENCY_CLASSES_BY_TYPE[row[:type]]
-        dep = dep_class.deserialize(app, row[:key], row[:attributes])
-        sum[dep.key] = dep
+      vertices = data[:vertices].each_with_object({}) do |row, sum|
+        vertex_class = VERTICES_BY_TYPE[row[:type]]
+        vertex = vertex_class.deserialize(app, row[:key], row[:attributes])
+        sum[vertex.key] = vertex
       end
 
-      graph = Graph.new(dependencies)
+      graph = Graph.new(vertices)
 
-      dependency_links = data[:dependency_links]
-      graph.dependency_map = dependency_links.each_with_object({}) do |row, sum|
-        dependency = graph.dependencies[row[:key]]
-        depended_on_by = row[:depended_on_by].map { |k| graph.dependencies[k] }
-        sum[dependency] = Set.new(depended_on_by) << dependency
+      edges = data[:edges]
+      graph.dependency_map = edges.each_with_object({}) do |row, sum|
+        vertex = graph.vertices[row[:key]]
+        depended_on_by = row[:depended_on_by].map { |k| graph.vertices[k] }
+        sum[vertex] = ::Hamster::Set.new(depended_on_by) << vertex
       end
 
       graph

middleman-core/lib/middleman-core/dependencies/edge.rb

@@ -0,0 +1,27 @@
+require 'middleman-core/contracts'
+require 'middleman-core/dependencies/vertices/vertex'
+
+module Middleman
+  module Dependencies
+    class Edge
+      include Contracts
+
+      Contract Vertex
+      attr_reader :vertex
+
+      Contract ImmutableSetOf[Vertex]
+      attr_accessor :depends_on
+
+      Contract Vertex, ImmutableSetOf[Vertex] => Any
+      def initialize(vertex, depends_on)
+        @vertex = vertex
+        @depends_on = depends_on
+      end
+
+      Contract String
+      def to_s
+        "#<#{self.class} vertex=#{@vertex} edges=#{@edges}>"
+      end
+    end
+  end
+end

middleman-core/lib/middleman-core/dependencies/graph.rb

@@ -0,0 +1,78 @@
+require 'set'
+require 'middleman-core/contracts'
+require 'middleman-core/dependencies/vertices/vertex'
+require 'middleman-core/dependencies/edge'
+
+module Middleman
+  module Dependencies
+    class Graph
+      include Contracts
+
+      Contract HashOf[Vertex::VERTEX_KEY, Vertex]
+      attr_reader :vertices
+
+      Contract ImmutableHashOf[Vertex, ImmutableSetOf[Vertex]]
+      attr_accessor :dependency_map
+
+      def initialize(vertices = {})
+        @vertices = vertices
+        @dependency_map = ::Hamster::Hash.empty
+      end
+
+      Contract Vertex => Vertex
+      def known_vertex_or_new(v)
+        @vertices[v.key] ||= v
+      end
+
+      Contract Edge => Any
+      def add_edge(edge)
+        deduped_vertex = known_vertex_or_new edge.vertex
+
+        @dependency_map.put(deduped_vertex) do |v|
+          (v || ::Hamster::Set.empty) << deduped_vertex
+        end
+
+        return if edge.depends_on.nil?
+
+        edge.depends_on.each do |depended_on|
+          deduped_depended_on = known_vertex_or_new depended_on
+
+          @dependency_map.put(deduped_depended_on) do |v|
+            (v || ::Hamster::Set.empty) << deduped_depended_on << deduped_vertex
+          end
+        end
+      end
+
+      Contract String => Bool
+      def exists?(file_path)
+        @dependency_map.key?(file_path)
+      end
+
+      Contract ImmutableSetOf[Vertex]
+      def invalidated
+        @_invalidated_cache ||= begin
+          invalidated_vertices = @dependency_map.keys.select do |vertex|
+            # Either "Missing from known vertices"
+            # Or invalided by the class
+            !@vertices.key?(vertex.key) || !vertex.valid?
+          end
+
+          invalidated_vertices.reduce(::Hamster::Set.empty) do |sum, vertex|
+            sum | invalidated_with_parents(vertex)
+          end
+        end
+      end
+
+      Contract Vertex => ImmutableSetOf[Vertex]
+      def invalidated_with_parents(vertex)
+        # TODO, recurse more?
+        @dependency_map[vertex] << vertex
+      end
+
+      Contract IsA['::Middleman::Sitemap::Resource'] => Bool
+      def invalidates_resource?(resource)
+        invalidated.any? { |d| d.invalidates_resource?(resource) }
+      end
+    end
+  end
+end

middleman-core/lib/middleman-core/dependencies/vertices.rb

@@ -0,0 +1,9 @@
+require 'middleman-core/dependencies/vertices/file_vertex'
+
+module Middleman
+  module Dependencies
+    VERTICES_BY_TYPE = {
+      FileVertex::TYPE_ID => FileVertex
+    }.freeze
+  end
+end

middleman-core/lib/middleman-core/dependencies/vertices/file_vertex.rb

@@ -0,0 +1,66 @@
+require 'pathname'
+require 'digest/sha1'
+require 'middleman-core/contracts'
+require 'middleman-core/dependencies/vertices/vertex'
+
+module Middleman
+  module Dependencies
+    class FileVertex < Vertex
+      include Contracts
+
+      TYPE_ID = :file
+
+      Contract IsA['::Middleman::Application'], String, Vertex::VERTEX_ATTRS => FileVertex
+      def self.deserialize(app, key, attributes)
+        FileVertex.new(app.root_path, key, attributes)
+      end
+
+      Contract IsA['Middleman::Sitemap::Resource'] => FileVertex
+      def self.from_resource(resource)
+        from_source_file(resource.app, resource.file_descriptor)
+      end
+
+      Contract IsA['::Middleman::Application'], IsA['::Middleman::SourceFile'] => FileVertex
+      def self.from_source_file(app, source_file)
+        FileVertex.new(app.root_path, source_file[:full_path].to_s)
+      end
+
+      Contract Or[String, Pathname], String, Maybe[VERTEX_ATTRS] => Any
+      def initialize(root, key, attributes = {})
+        @root = Pathname(root)
+        @full_path = full_path(@root, key)
+        super(relative_path(@root, key), attributes)
+      end
+
+      Contract Bool
+      def valid?
+        @is_valid = (previous_hash.nil? || hash_file == previous_hash) if @is_valid.nil?
+        @is_valid
+      end
+
+      Contract IsA['Middleman::Sitemap::Resource'] => Bool
+      def invalidates_resource?(resource)
+        resource.file_descriptor[:full_path].to_s == @full_path
+      end
+
+      Contract Vertex::SERIALIZED_VERTEX
+      def serialize
+        super({
+          hash: valid? && !previous_hash.nil? ? previous_hash : hash_file
+        })
+      end
+
+      private
+
+      Contract Maybe[String]
+      def previous_hash
+        @attributes[:hash]
+      end
+
+      Contract String
+      def hash_file
+        ::Digest::SHA1.file(@full_path).hexdigest
+      end
+    end
+  end
+end

middleman-core/lib/middleman-core/dependencies/vertices/vertex.rb

@@ -0,0 +1,71 @@
+require 'pathname'
+require 'middleman-core/contracts'
+
+module Middleman
+  module Dependencies
+    class Vertex
+      include Contracts
+
+      VERTEX_KEY = Or[String, Symbol]
+      VERTEX_ATTRS = HashOf[Symbol, String]
+      SERIALIZED_VERTEX = {
+        key: Any, # Weird inheritance bug
+        type: Symbol,
+        attributes: VERTEX_ATTRS
+      }.freeze
+
+      Contract VERTEX_KEY
+      attr_reader :key
+
+      Contract VERTEX_ATTRS
+      attr_reader :attributes
+
+      Contract VERTEX_KEY, VERTEX_ATTRS => Any
+      def initialize(key, attributes)
+        @key = key
+        @attributes = attributes
+      end
+
+      Contract Vertex => Bool
+      def ==(other)
+        key == other.key
+      end
+
+      Contract Bool
+      def valid?
+        raise NotImplementedError
+      end
+
+      Contract IsA['Middleman::Sitemap::Resource'] => Bool
+      def invalidates_resource?(_resource)
+        raise NotImplementedError
+      end
+
+      Contract Maybe[VERTEX_ATTRS] => SERIALIZED_VERTEX
+      def serialize(attributes = {})
+        {
+          key: @key,
+          type: type_id,
+          attributes: @attributes.merge(attributes)
+        }
+      end
+
+      protected
+
+      Contract Symbol
+      def type_id
+        self.class.const_get :TYPE_ID
+      end
+
+      Contract Pathname, String => String
+      def relative_path(root, file)
+        Pathname(File.expand_path(file)).relative_path_from(root).to_s
+      end
+
+      Contract Pathname, String => String
+      def full_path(root, file)
+        File.expand_path(file, root)
+      end
+    end
+  end
+end

middleman-core/lib/middleman-core/file_renderer.rb

@@ -1,8 +1,9 @@
 require 'tilt'
-require 'set'
+require 'hamster'
 require 'active_support/core_ext/string/output_safety'
 require 'active_support/core_ext/module/delegation'
 require 'middleman-core/contracts'
+require 'middleman-core/dependencies/vertices/vertex'
 
 ::Tilt.default_mapping.lazy_map.delete('html')
 ::Tilt.default_mapping.lazy_map.delete('csv')
@@ -16,15 +17,15 @@ module Middleman
       @_cache ||= ::Tilt::Cache.new
     end
 
-    Contract Maybe[SetOf[IsA['::Middleman::Dependencies::BaseDependency']]]
-    attr_reader :dependencies
+    Contract ImmutableSetOf[::Middleman::Dependencies::Vertex]
+    attr_reader :vertices
 
     def_delegator :"self.class", :cache
 
     def initialize(app, path)
       @app = app
       @path = path.to_s
-      @dependencies = nil
+      @vertices = ::Hamster::Set.empty
     end
 
     # Render an on-disk file. Used for everything, including layouts.
@@ -71,12 +72,12 @@ module Middleman
       #   ::Tilt.new(path, 1, options) { body }
       # end
 
-      @dependencies = nil
+      @vertices = ::Hamster::Set.empty
 
       # Render using Tilt
       content = ::Middleman::Util.instrument 'render.tilt', path: path do
         template.render(context, locs, &block).tap do
-          @dependencies = template.dependencies if template.respond_to?(:dependencies)
+          @vertices = template.vertices if template.respond_to?(:vertices)
         end
       end
 

middleman-core/lib/middleman-core/filter.rb

@@ -1,4 +1,6 @@
+require 'hamster'
 require 'middleman-core/contracts'
+require 'middleman-core/dependencies/vertices/vertex'
 
 module Middleman
   class Filter
@@ -31,7 +33,7 @@ module Middleman
       @after_filter = @options.fetch(:after_filter, nil)
     end
 
-    Contract String => String
+    Contract String => [String, ImmutableSetOf[::Middleman::Dependencies::Vertex]]
     def execute_filter(_body)
       raise NotImplementedError
     end
@@ -45,10 +47,10 @@ module Middleman
       @callable = callable
     end
 
-    Contract String => [String, Maybe[SetOf[String]]]
+    Contract String => [String, ImmutableSetOf[::Middleman::Dependencies::Vertex]]
     def execute_filter(body)
       result = @callable.call(body)
-      result.is_a?(Array) ? result : [result, nil]
+      result.is_a?(Array) ? result : [result, ::Hamster::Set.empty]
     end
   end
 end

middleman-core/lib/middleman-core/inline_url_filter.rb

@@ -1,6 +1,9 @@
+require 'hamster'
 require 'middleman-core/util'
 require 'middleman-core/filter'
 require 'middleman-core/contracts'
+require 'middleman-core/dependencies/vertices/vertex'
+require 'middleman-core/dependencies/vertices/file_vertex'
 
 module Middleman
   class InlineURLRewriter < Filter
@@ -28,13 +31,13 @@ module Middleman
       @app.sitemap.by_destination_path(full_asset_path) || @app.sitemap.by_path(full_asset_path)
     end
 
-    Contract String => [String, Maybe[SetOf[String]]]
+    Contract String => [String, ImmutableSetOf[::Middleman::Dependencies::Vertex]]
     def execute_filter(body)
       path = "/#{@resource.destination_path}"
       dirpath = ::Pathname.new(File.dirname(path))
 
       ::Middleman::Util.instrument 'inline_url_filter', path: path do
-        deps = Set.new
+        vertices = ::Hamster::Set.empty
 
         new_content = ::Middleman::Util.rewrite_paths(body, path, @options.fetch(:url_extensions), @app) do |asset_path|
           uri = ::Middleman::Util.parse_uri(asset_path)
@@ -55,7 +58,7 @@ module Middleman
 
           if result
             if @options.fetch(:create_dependencies, false)
-              deps << ::Middleman::Dependencies::FileDependency.from_resource(
+              vertices <<= ::Middleman::Dependencies::FileVertex.from_resource(
                 target_resource(asset_path, dirpath)
               )
             end
@@ -66,7 +69,7 @@ module Middleman
           asset_path
         end
 
-        [new_content, deps]
+        [new_content, vertices]
       end
     end
   end

middleman-core/lib/middleman-core/renderers/sass.rb

@@ -1,6 +1,7 @@
-require 'set'
+require 'hamster'
 require 'sass'
 require 'middleman-core/dependencies'
+require 'middleman-core/dependencies/vertices/file_vertex'
 
 begin
   require 'sassc'
@@ -76,12 +77,10 @@ module Middleman
           end
         end
 
-        def dependencies
-          files = @engine.dependencies.map do |d|
-            ::Middleman::Dependencies::FileDependency.new(@context.app.root_path, d.filename)
+        def vertices
+          @engine.dependencies.reduce(::Hamster::Set.empty) do |sum, d|
+            sum << ::Middleman::Dependencies::FileVertex.new(@context.app.root_path, d.filename)
           end
-
-          files.empty? ? nil : Set.new(files)
         end
 
         # Change Sass path, for url functions, to the build folder if we're building

middleman-core/lib/middleman-core/sitemap/resource.rb

@@ -1,10 +1,12 @@
 require 'rack/mime'
+require 'set'
+require 'hamster'
 require 'middleman-core/sitemap/extensions/traversal'
 require 'middleman-core/file_renderer'
 require 'middleman-core/template_renderer'
 require 'middleman-core/contracts'
-require 'set'
 require 'middleman-core/inline_url_filter'
+require 'middleman-core/dependencies/vertices/vertex'
 
 module Middleman
   # Sitemap namespace
@@ -39,8 +41,8 @@ module Middleman
       Contract Num
       attr_reader :priority
 
-      Contract Maybe[SetOf[IsA['::Middleman::Dependencies::BaseDependency']]]
-      attr_reader :dependencies
+      Contract ImmutableSetOf[::Middleman::Dependencies::Vertex]
+      attr_reader :vertices
 
       # Initialize resource with parent store and URL
       # @param [Middleman::Sitemap::Store] store
@@ -54,7 +56,7 @@ module Middleman
         @ignored  = false
         @filters  = ::Hamster::SortedSet.empty
         @priority = priority
-        @dependencies = Set.new
+        @vertices = ::Hamster::Set.empty
 
         source = Pathname(source) if source&.is_a?(String)
 
@@ -175,7 +177,7 @@ module Middleman
       # @return [String]
       Contract Hash, Hash, Maybe[Proc] => String
       def render(options_hash = ::Middleman::EMPTY_HASH, locs = ::Middleman::EMPTY_HASH, &_block)
-        @dependencies = Set.new
+        @vertices = ::Hamster::Set.empty
 
         body = render_without_filters(options_hash, locs)
 
@@ -186,7 +188,7 @@ module Middleman
             output
           elsif filter.is_a?(Filter)
             result = filter.execute_filter(output)
-            @dependencies |= result[1] unless result[1].nil?
+            @vertices |= result[1]
             result[0]
           else
             output
@@ -219,7 +221,7 @@ module Middleman
 
         renderer = ::Middleman::TemplateRenderer.new(@app, file_descriptor[:full_path].to_s)
         renderer.render(locs, opts).to_str.tap do
-          @dependencies |= renderer.dependencies unless renderer.dependencies.nil?
+          @vertices |= renderer.vertices
         end
       end
 

middleman-core/lib/middleman-core/template_context.rb

@@ -1,7 +1,10 @@
 require 'pathname'
+require 'hamster'
 require 'middleman-core/file_renderer'
 require 'middleman-core/template_renderer'
 require 'middleman-core/contracts'
+require 'middleman-core/dependencies/vertices/vertex'
+require 'middleman-core/dependencies/vertices/file_vertex'
 
 module Middleman
   # The TemplateContext Class
@@ -22,8 +25,8 @@ module Middleman
     # Required for Padrino's rendering
     attr_accessor :current_engine
 
-    Contract Maybe[SetOf[IsA['::Middleman::Dependencies::BaseDependency']]]
-    attr_reader :dependencies
+    Contract ImmutableSetOf[::Middleman::Dependencies::Vertex]
+    attr_reader :vertices
 
     # Shorthand references to global values on the app instance.
     def_delegators :@app, :config, :logger, :sitemap, :server?, :build?, :environment?, :environment, :data, :extensions, :root, :development?, :production?
@@ -38,7 +41,7 @@ module Middleman
       @locs = locs
       @opts = options_hash
 
-      @dependencies = Set.new
+      @vertices = ::Hamster::Set.empty
     end
 
     # Return the current buffer to the caller and clear the value internally.
@@ -91,7 +94,7 @@ module Middleman
         restore_buffer(buf_was)
       end
 
-      @dependencies << ::Middleman::Dependencies::FileDependency.from_source_file(@app, layout_file)
+      @vertices <<= ::Middleman::Dependencies::FileVertex.from_source_file(@app, layout_file)
 
       # Render the layout, with the contents of the block inside.
       concat_safe_content render_file(layout_file, @locs, @opts) { content }
@@ -118,7 +121,7 @@ module Middleman
       source_path = sitemap.file_to_path(partial_file)
       r = sitemap.by_path(source_path)
 
-      @dependencies << ::Middleman::Dependencies::FileDependency.from_source_file(@app, partial_file)
+      @vertices <<= ::Middleman::Dependencies::FileVertex.from_source_file(@app, partial_file)
 
       result = if (r && !r.template?) || (Tilt[partial_file[:full_path]].nil? && partial_file[:full_path].exist?)
                  partial_file.read
@@ -218,7 +221,7 @@ module Middleman
 
           content_renderer = ::Middleman::FileRenderer.new(@app, path)
           content = content_renderer.render(locs, opts, context, &block)
-          @dependencies |= content_renderer.dependencies unless content_renderer.dependencies.nil?
+          @vertices |= content_renderer.vertices
 
           path = File.basename(path, File.extname(path))
         rescue LocalJumpError

middleman-core/lib/middleman-core/template_renderer.rb

@@ -1,10 +1,11 @@
 require 'tilt'
-require 'set'
+require 'hamster'
 require 'active_support/core_ext/string/output_safety'
+require 'middleman-core/contracts'
 require 'middleman-core/template_context'
 require 'middleman-core/file_renderer'
-require 'middleman-core/dependencies'
-require 'middleman-core/contracts'
+require 'middleman-core/dependencies/vertices/vertex'
+require 'middleman-core/dependencies/vertices/file_vertex'
 
 module Middleman
   class TemplateRenderer
@@ -100,13 +101,13 @@ module Middleman
     # Custom error class for handling
     class TemplateNotFound < RuntimeError; end
 
-    Contract Maybe[SetOf[IsA['::Middleman::Dependencies::BaseDependency']]]
-    attr_reader :dependencies
+    Contract ImmutableSetOf[::Middleman::Dependencies::Vertex]
+    attr_reader :vertices
 
     def initialize(app, path)
       @app = app
       @path = path
-      @dependencies = nil
+      @vertices = ::Hamster::Set.empty
     end
 
     # Render a template, with layout, given a path
@@ -174,8 +175,8 @@ module Middleman
 
                     ::Middleman::Util.instrument 'builder.output.resource.render-layout', path: File.basename(layout_file[:relative_path].to_s) do
                       layout_renderer.render(locals, options, context) { content }.tap do
-                        @dependencies << ::Middleman::Dependencies::FileDependency.from_source_file(@app, layout_file)
-                        @dependencies |= layout_renderer.dependencies unless layout_renderer.dependencies.nil?
+                        @vertices <<= ::Middleman::Dependencies::FileVertex.from_source_file(@app, layout_file)
+                        @vertices |= layout_renderer.vertices
                       end
                     end
                   else
@@ -183,8 +184,7 @@ module Middleman
                   end
       end
 
-      @dependencies |= context.dependencies unless context.dependencies.nil?
-      @dependencies = @dependencies.empty? ? nil : @dependencies
+      @vertices |= context.vertices
 
       # Return result
       content
@@ -201,7 +201,7 @@ module Middleman
       # handles cases like `style.css.sass.erb`
       content = nil
 
-      @dependencies = Set.new
+      @vertices = ::Hamster::Set.empty
 
       while ::Middleman::Util.tilt_class(path)
         begin
@@ -209,7 +209,7 @@ module Middleman
 
           content_renderer = ::Middleman::FileRenderer.new(@app, path)
           content = content_renderer.render(locs, opts, context, &block)
-          @dependencies |= content_renderer.dependencies unless content_renderer.dependencies.nil?
+          @vertices |= content_renderer.vertices
 
           path = path.sub(/\.[^.]*\z/, '')
         rescue LocalJumpError