From 865595288659fe596c920eaf7374c29fa1cddd3c Mon Sep 17 00:00:00 2001
From: Andy Waite <13400+andyw8@users.noreply.github.com>
Date: Tue, 11 Jun 2024 12:46:17 -0400
Subject: [PATCH] Use RBS to index Ruby core methods

---
 .../lib/ruby_indexer/rbs_indexer.rb           | 34 +++++++++++++++++++
 lib/ruby_indexer/test/rbs_indexer_test.rb     | 14 ++++++++
 2 files changed, 48 insertions(+)

diff --git a/lib/ruby_indexer/lib/ruby_indexer/rbs_indexer.rb b/lib/ruby_indexer/lib/ruby_indexer/rbs_indexer.rb
index 0988621958..e670a51332 100644
--- a/lib/ruby_indexer/lib/ruby_indexer/rbs_indexer.rb
+++ b/lib/ruby_indexer/lib/ruby_indexer/rbs_indexer.rb
@@ -66,6 +66,11 @@ def handle_class_declaration(declaration, pathname)
       end
 
       @index << class_entry
+      declaration.members.each do |member|
+        next unless member.is_a?(RBS::AST::Members::MethodDefinition)
+
+        handle_member(member, class_entry)
+      end
     end
 
     sig { params(declaration: RBS::AST::Declarations::Module, pathname: Pathname).void }
@@ -76,8 +81,15 @@ def handle_module_declaration(declaration, pathname)
       comments = Array(declaration.comment&.string)
       class_entry = Entry::Module.new(nesting, file_path, location, comments)
       @index << class_entry
+      declaration.members.each do |member|
+        next unless member.is_a?(RBS::AST::Members::MethodDefinition)
+
+        handle_member(member, class_entry)
+      end
     end
 
+    Array.new(1)
+
     sig { params(rbs_location: RBS::Location).returns(RubyIndexer::Location) }
     def to_ruby_indexer_location(rbs_location)
       RubyIndexer::Location.new(
@@ -87,5 +99,27 @@ def to_ruby_indexer_location(rbs_location)
         rbs_location.end_column,
       )
     end
+
+    sig { params(member: RBS::AST::Members::MethodDefinition, class_entry: T.any(Entry::Class, Entry::Module)).void }
+    def handle_member(member, class_entry)
+      name = member.name.name
+      file_path = member.location.buffer.name
+      location = to_ruby_indexer_location(member.location)
+      comments = Array(member.comment&.string)
+      parameters_node = nil
+      visibility = Entry::Visibility::PUBLIC
+      owner = class_entry
+
+      klass = member.instance? ? Entry::InstanceMethod : Entry::SingletonMethod
+      entry = klass.new(
+          name,
+          file_path,
+          location,
+          comments,
+          parameters_node,
+          visibility,
+          owner)
+      @index << entry if entry
+    end
   end
 end
diff --git a/lib/ruby_indexer/test/rbs_indexer_test.rb b/lib/ruby_indexer/test/rbs_indexer_test.rb
index 9007278ca1..da5a9a6e85 100644
--- a/lib/ruby_indexer/test/rbs_indexer_test.rb
+++ b/lib/ruby_indexer/test/rbs_indexer_test.rb
@@ -43,5 +43,19 @@ def test_index_core_modules
       assert_equal(0, entry.location.start_column)
       assert_operator(entry.location.end_column, :>, 0)
     end
+
+    def test_index_methods
+      entries = @index["initialize"]
+      refute_nil(entries)
+      entry = entries.find { |entry| entry.owner.name == "Array" }
+      assert_match(%r{/gems/rbs-.*/core/array.rbs}, entry.file_path)
+      assert_equal("array.rbs", entry.file_name)
+
+      # Using fixed positions would be fragile, so let's just check some basics.
+      assert_operator(entry.location.start_line, :>, 0)
+      assert_operator(entry.location.end_line, :>, entry.location.start_line)
+      assert_equal(2, entry.location.start_column)
+      assert_operator(entry.location.end_column, :>, 0)
+    end
   end
 end