MM: File layout

Each module into its own directory.
  Each module that has extensions in its own subdir
  No need to separate classes/enums etc even in ObjC

lib/jazzy/source_declaration/type.rb

@@ -164,8 +164,14 @@ def objc_unexposed?
         kind == 'sourcekitten.source.lang.objc.decl.unexposed'
       end
 
+      OVERVIEW_KIND = 'Overview'
+
       def self.overview
-        Type.new('Overview')
+        Type.new(OVERVIEW_KIND)
+      end
+
+      def overview?
+        kind == OVERVIEW_KIND
       end
 
       MARKDOWN_KIND = 'document.markdown'
@@ -194,7 +200,8 @@ def ==(other)
           dash: 'Guide',
         }.freeze,
 
-        'Overview' => {
+        # Group/Overview
+        OVERVIEW_KIND => {
           jazzy: nil,
           dash: 'Section',
         }.freeze,

lib/jazzy/sourcekitten.rb

@@ -189,7 +189,7 @@ def self.sanitize_filename(doc)
     end
 
     # rubocop:disable Metrics/MethodLength
-    # Generate doc URL by prepending its parents URLs
+    # Generate doc URL by prepending its parents' URLs
     # @return [Hash] input docs with URLs
     def self.make_doc_urls(docs)
       docs.each do |doc|
@@ -229,18 +229,46 @@ def self.make_doc_urls(docs)
     # Guides in the root for back-compatibility.
     # Declarations under outer namespace type (Structures, Classes, etc.)
     def self.subdir_for_doc(doc)
-      return [] if doc.type.markdown?
-
-      top_level_decl = doc.namespace_path.first
-      if top_level_decl.type.name
-        [top_level_decl.type.plural_url_name] +
-          doc.namespace_ancestors.map(&:name)
+      if Config.instance.multiple_modules?
+        subdir_for_doc_multi_module(doc)
       else
-        # Category - in the root
-        []
+        # Back-compatibility layout version
+        subdir_for_doc_single_module(doc)
       end
     end
 
+    # Pre-multi-module site layout, does not allow for
+    # types with the same name.
+    def self.subdir_for_doc_single_module(doc)
+      # Guides + Groups in the root
+      return [] if doc.type.markdown? || doc.type.overview?
+
+      [doc.namespace_path.first.type.plural_url_name] +
+        doc.namespace_ancestors.map(&:name)
+    end
+
+    # Multi-module site layout, separate each module that
+    # is being documented.
+    def self.subdir_for_doc_multi_module(doc)
+      # Guides + Groups in the root
+      return [] if doc.type.markdown? || doc.type.overview?
+
+      root_decl = doc.namespace_path.first
+
+      # Extensions need an extra dir to allow for extending
+      # ExternalModule1.TypeName and ExternalModule2.TypeName
+      namespace_subdir =
+        if root_decl.type.swift_extension?
+          ['Extensions', root_decl.module_name]
+        else
+          ['Types']
+        end
+
+      [root_decl.doc_module_name] +
+        namespace_subdir +
+        doc.namespace_ancestors.map(&:name)
+    end
+
     # returns all subdirectories of specified path
     def self.rec_path(path)
       path.children.collect do |child|