Migrate type hierarchy to use Rubydex

Author: vinistock

lib/ruby_lsp/internal.rb

@@ -32,6 +32,7 @@
 require "set"
 
 # Rubydex LSP additions
+require "ruby_lsp/rubydex/declaration"
 require "ruby_lsp/rubydex/definition"
 require "ruby_lsp/rubydex/reference"
 

lib/ruby_lsp/requests/prepare_type_hierarchy.rb

@@ -5,9 +5,7 @@ module RubyLsp
   module Requests
     # The [prepare type hierarchy
     # request](https://microsoft.github.io/language-server-protocol/specification#textDocument_prepareTypeHierarchy)
-    # displays the list of ancestors (supertypes) and descendants (subtypes) for the selected type.
-    #
-    # Currently only supports supertypes due to a limitation of the index.
+    # displays the list of direct ancestors (supertypes) and descendants (subtypes) for the selected type.
     class PrepareTypeHierarchy < Request
       include Support::Common
 
@@ -18,12 +16,12 @@ def provider
         end
       end
 
-      #: ((RubyDocument | ERBDocument) document, RubyIndexer::Index index, Hash[Symbol, untyped] position) -> void
-      def initialize(document, index, position)
+      #: ((RubyDocument | ERBDocument) document, GlobalState global_state, Hash[Symbol, untyped] position) -> void
+      def initialize(document, global_state, position)
         super()
 
         @document = document
-        @index = index
+        @graph = global_state.graph #: Rubydex::Graph
         @position = position
       end
 
@@ -36,32 +34,78 @@ def perform
             Prism::ConstantReadNode,
             Prism::ConstantWriteNode,
             Prism::ConstantPathNode,
+            Prism::SingletonClassNode,
           ],
         )
 
-        node = context.node
-        parent = context.parent
-        return unless node && parent
+        node = context.node #: as (Prism::ConstantReadNode | Prism::ConstantPathNode | Prism::ConstantWriteNode | Prism::SingletonClassNode)?
+        return unless node
+
+        pair = name_and_nesting(node, context)
+        return unless pair
 
-        target = determine_target(node, parent, @position)
-        entries = @index.resolve(target.slice, context.nesting)
-        return unless entries
+        declaration = @graph.resolve_constant(pair.first, pair.last)
+        return unless declaration.is_a?(Rubydex::Namespace)
 
-        # While the spec allows for multiple entries, VSCode seems to only support one
-        # We'll just return the first one for now
-        first_entry = entries.first #: as !nil
-        range = range_from_location(first_entry.location)
+        primary = declaration.definitions.first
+        return unless primary
 
         [
-          Interface::TypeHierarchyItem.new(
-            name: first_entry.name,
-            kind: kind_for_entry(first_entry),
-            uri: first_entry.uri.to_s,
-            range: range,
-            selection_range: range,
+          primary.to_lsp_type_hierarchy_item(
+            declaration.name,
+            detail: declaration.lsp_type_hierarchy_detail,
           ),
         ]
       end
+
+      private
+
+      # Returns the `(name, nesting)` pair to pass to `Rubydex::Graph#resolve_constant`, covering three cases:
+      #
+      #: ((Prism::ConstantReadNode | Prism::ConstantPathNode | Prism::ConstantWriteNode | Prism::SingletonClassNode), NodeContext) -> [String, Array[String]]?
+      def name_and_nesting(node, context)
+        parent = context.parent
+        nesting = context.nesting
+
+        singleton_node = singleton_class_node_for(node, parent)
+        return singleton_lookup(singleton_node, nesting) if singleton_node
+
+        target = parent ? determine_target(node, parent, @position) : node
+        [target.slice, nesting]
+      end
+
+      # Ensures that we're returning the target of the singleton class block regardless of whether the cursor is on the
+      # `class` keyword or the constant reference for the target
+      #: ((Prism::ConstantReadNode | Prism::ConstantPathNode | Prism::ConstantWriteNode | Prism::SingletonClassNode), Prism::Node?) -> Prism::SingletonClassNode?
+      def singleton_class_node_for(node, parent)
+        return node if node.is_a?(Prism::SingletonClassNode)
+        return unless parent.is_a?(Prism::SingletonClassNode) && parent.expression == node
+
+        parent
+      end
+
+      # Builds the synthesized singleton class name (e.g. `Foo::<Foo>`) for a `class << X` block, together with the
+      # outer lexical nesting. `NodeContext` already appends a `<ClassName>` marker as the last element of the nesting
+      # whenever the cursor sits inside (or on) a `SingletonClassNode`, so we drop that marker to obtain the scope in
+      # which the singleton should be resolved.
+      #: (Prism::SingletonClassNode, Array[String]) -> [String, Array[String]]?
+      def singleton_lookup(singleton_node, nesting)
+        outer = nesting[0...-1] || []
+
+        case expression = singleton_node.expression
+        when Prism::SelfNode
+          name = nesting.last
+          return unless name
+
+          [name, outer]
+        when Prism::ConstantReadNode, Prism::ConstantPathNode
+          name = constant_name(expression)
+          return unless name
+
+          unqualified = name.split("::").last #: as !nil
+          ["#{name}::<#{unqualified}>", outer]
+        end
+      end
     end
   end
 end

lib/ruby_lsp/requests/type_hierarchy_supertypes.rb

@@ -9,65 +9,101 @@ module Requests
     class TypeHierarchySupertypes < Request
       include Support::Common
 
-      #: (RubyIndexer::Index index, Hash[Symbol, untyped] item) -> void
-      def initialize(index, item)
+      #: (GlobalState, Hash[Symbol, untyped]) -> void
+      def initialize(global_state, item)
         super()
 
-        @index = index
+        @graph = global_state.graph #: Rubydex::Graph
         @item = item
       end
 
       # @override
       #: -> Array[Interface::TypeHierarchyItem]?
       def perform
-        name = @item[:name]
-        entries = @index[name]
-
-        parents = Set.new #: Set[RubyIndexer::Entry::Namespace]
-        return unless entries&.any?
-
-        entries.each do |entry|
-          next unless entry.is_a?(RubyIndexer::Entry::Namespace)
-
-          if entry.is_a?(RubyIndexer::Entry::Class)
-            parent_class_name = entry.parent_class
-            if parent_class_name
-              resolved_parent_entries = @index.resolve(parent_class_name, entry.nesting)
-              resolved_parent_entries&.each do |entry|
-                next unless entry.is_a?(RubyIndexer::Entry::Class)
-
-                parents << entry
-              end
-            end
-          end
-
-          entry.mixin_operations.each do |mixin_operation|
-            mixin_name = mixin_operation.module_name
-            resolved_mixin_entries = @index.resolve(mixin_name, entry.nesting)
-            next unless resolved_mixin_entries
-
-            resolved_mixin_entries.each do |mixin_entry|
-              next unless mixin_entry.is_a?(RubyIndexer::Entry::Module)
-
-              parents << mixin_entry
-            end
-          end
-        end
+        fully_qualified_name = @item.dig(:data, :fully_qualified_name) || @item[:name] #: String?
+        return unless fully_qualified_name
+
+        declaration = @graph[fully_qualified_name]
+        return unless declaration.is_a?(Rubydex::Namespace)
 
-        parents.map { |entry| hierarchy_item(entry) }
+        compute_supertypes(declaration).filter_map { |name, backing| hierarchy_item(name, backing) }
       end
 
       private
 
-      #: (RubyIndexer::Entry entry) -> Interface::TypeHierarchyItem
-      def hierarchy_item(entry)
-        Interface::TypeHierarchyItem.new(
-          name: entry.name,
-          kind: kind_for_entry(entry),
-          uri: entry.uri.to_s,
-          range: range_from_location(entry.location),
-          selection_range: range_from_location(entry.name_location),
-          detail: entry.file_name,
+      # Returns an array of `[display_name, backing_declaration]` pairs. `display_name` is the name shown in the type
+      # hierarchy item (which may be a synthesized singleton class name like `Object::<Object>`). `backing_declaration`
+      # is the namespace whose primary definition provides the location for the hierarchy item — it may differ from the
+      # display name when the singleton class is implicit and has no definitions of its own, in which case we fall back
+      # to the attached object's definition so the user still lands somewhere useful.
+      #
+      #: (Rubydex::Namespace) -> Array[[String, Rubydex::Namespace]]
+      def compute_supertypes(declaration)
+        case declaration
+        when Rubydex::SingletonClass
+          singleton_supertypes(declaration)
+        when Rubydex::Class
+          class_supertypes(declaration)
+        else
+          explicit_supertypes(declaration)
+        end
+      end
+
+      #: (Rubydex::Class) -> Array[[String, Rubydex::Namespace]]
+      def class_supertypes(declaration)
+        # `BasicObject` is the root of the Ruby class hierarchy
+        supertypes = explicit_supertypes(declaration)
+        return supertypes if declaration.name == "BasicObject"
+
+        # If the class has any superclass reference (resolved or unresolved), don't re-add the implicit `Object`.
+        has_superclass = declaration.definitions.any? do |d|
+          d.is_a?(Rubydex::ClassDefinition) && !d.superclass.nil?
+        end
+        return supertypes if has_superclass
+
+        object = @graph["Object"] #: as Rubydex::Namespace
+        supertypes << ["Object", object]
+        supertypes
+      end
+
+      #: (Rubydex::Namespace) -> Array[[String, Rubydex::Namespace]]
+      def explicit_supertypes(declaration)
+        declaration.direct_supertypes.map { |s| [s.name, s] }
+      end
+
+      # Singleton classes don't have their own superclass references. Their direct supertype is the singleton class of
+      # the attached object's superclass, computed recursively so that nested singleton classes (e.g.
+      # `Foo::<Foo>::<<Foo>>`) still resolve to the matching depth on the parent chain. When the synthesized singleton
+      # class name has no backing declaration with definitions (implicit singleton), we fall back to the attached
+      # supertype's backing so the user is still navigated to a meaningful location.
+      #
+      #: (Rubydex::SingletonClass) -> Array[[String, Rubydex::Namespace]]
+      def singleton_supertypes(declaration)
+        attached = declaration.owner
+        return [] unless attached.is_a?(Rubydex::Namespace)
+
+        compute_supertypes(attached).map do |parent_name, parent_backing|
+          singleton_name = singleton_name_of(parent_name)
+          found = @graph[singleton_name]
+          backing = found.is_a?(Rubydex::Namespace) && found.definitions.any? ? found : parent_backing
+          [singleton_name, backing]
+        end
+      end
+
+      #: (String) -> String
+      def singleton_name_of(name)
+        unqualified = name.split("::").last || name
+        "#{name}::<#{unqualified}>"
+      end
+
+      #: (String, Rubydex::Namespace) -> Interface::TypeHierarchyItem?
+      def hierarchy_item(name, declaration)
+        primary = declaration.definitions.first #: Rubydex::Definition?
+        return unless primary
+
+        primary.to_lsp_type_hierarchy_item(
+          name,
+          detail: declaration.lsp_type_hierarchy_detail,
         )
       end
     end

lib/ruby_lsp/rubydex/declaration.rb

@@ -0,0 +1,48 @@
+# typed: strict
+# frozen_string_literal: true
+
+module Rubydex
+  class Declaration
+    # Detail text shown on a `TypeHierarchyItem` for this declaration. Hints at multiplicity
+    # when the declaration spans more than one re-open; otherwise falls back to the primary
+    # definition's file name so users can quickly see where the type comes from.
+    #
+    #: () -> String?
+    def lsp_type_hierarchy_detail
+      defs = definitions
+      count = defs.count
+      return "#{count} definitions" if count > 1
+
+      primary = defs.first
+      return unless primary
+
+      uri = URI(primary.location.uri)
+      path = uri.full_path
+      path ? File.basename(path) : uri.to_s
+    end
+  end
+
+  class Namespace
+    # Resolved, deduplicated direct supertypes across every re-open of this declaration.
+    # Aggregates each definition's own `superclass`/`include`/`prepend` references and drops
+    # unresolved ones. Order is stable (first-seen across definitions).
+    #: () -> Array[Rubydex::Namespace]
+    def direct_supertypes
+      seen = {} #: Hash[String, Rubydex::Namespace]
+
+      definitions.each do |definition|
+        definition.direct_supertype_references.each do |ref|
+          next unless ref.is_a?(ResolvedConstantReference)
+
+          target = ref.declaration
+          next unless target.is_a?(Namespace)
+          next if seen.key?(target.name)
+
+          seen[target.name] = target
+        end
+      end
+
+      seen.values
+    end
+  end
+end