Indicate multiple signatures for Hover and Completion Resolve (#2415)

* Indicate multiple signatures for Hover and Completion Resolve

* Extract common behaviour

lib/ruby_indexer/lib/ruby_indexer/entry.rb

@@ -342,6 +342,19 @@ def decorated_parameters
 
         "(#{first_signature.format})"
       end
+
+      sig { returns(String) }
+      def formatted_signatures
+        overloads_count = signatures.size
+        case overloads_count
+        when 1
+          ""
+        when 2
+          "\n(+1 overload)"
+        else
+          "\n(+#{overloads_count - 1} overloads)"
+        end
+      end
     end
 
     class Accessor < Member
@@ -542,6 +555,16 @@ def parameters
       def decorated_parameters
         @target.decorated_parameters
       end
+
+      sig { returns(String) }
+      def formatted_signatures
+        @target.formatted_signatures
+      end
+
+      sig { returns(T::Array[Signature]) }
+      def signatures
+        @target.signatures
+      end
     end
 
     # Ruby doesn't support method overloading, so a method will have only one signature.

lib/ruby_lsp/listeners/hover.rb

@@ -174,7 +174,10 @@ def handle_method_hover(message, inherited_only: false)
         methods = @index.resolve_method(message, type.name, inherited_only: inherited_only)
         return unless methods
 
-        title = "#{message}#{T.must(methods.first).decorated_parameters}"
+        first_method = T.must(methods.first)
+
+        title = "#{message}#{first_method.decorated_parameters}"
+        title << first_method.formatted_signatures
 
         if type.is_a?(TypeInferrer::GuessedType)
           title << "\n\nGuessed receiver: #{type.name}"

lib/ruby_lsp/requests/completion_resolve.rb

@@ -63,6 +63,7 @@ def perform
 
         if first_entry.is_a?(RubyIndexer::Entry::Member)
           label = +"#{label}#{first_entry.decorated_parameters}"
+          label << first_entry.formatted_signatures
         end
 
         guessed_type = @item.dig(:data, :guessed_type)

test/requests/completion_resolve_test.rb

@@ -108,6 +108,28 @@ def bar
     end
   end
 
+  def test_indicates_signature_count_in_label_details
+    source = +<<~RUBY
+      String.try_convert
+    RUBY
+
+    with_server(source, stub_no_typechecker: true) do |server, _uri|
+      index = server.instance_variable_get(:@global_state).index
+      RubyIndexer::RBSIndexer.new(index).index_ruby_core
+      existing_item = {
+        label: "try_convert",
+        kind: RubyLsp::Constant::CompletionItemKind::METHOD,
+        data: { owner_name: "String::<Class:String>" },
+      }
+
+      server.process_message(id: 1, method: "completionItem/resolve", params: existing_item)
+
+      result = server.pop_response.response
+      assert_match("try_convert(object)", result[:documentation].value)
+      assert_match("(+2 overloads)", result[:documentation].value)
+    end
+  end
+
   def test_completion_documentation_for_guessed_types
     source = +<<~RUBY
       class User

test/requests/hover_expectations_test.rb

@@ -467,6 +467,26 @@ def baz
     end
   end
 
+  def test_hover_for_methods_shows_overload_count
+    source = <<~RUBY
+      String.try_convert
+    RUBY
+
+    with_server(source) do |server, uri|
+      index = server.instance_variable_get(:@global_state).index
+      RubyIndexer::RBSIndexer.new(index).index_ruby_core
+      server.process_message(
+        id: 1,
+        method: "textDocument/hover",
+        params: { textDocument: { uri: uri }, position: { character: 8, line: 0 } },
+      )
+
+      contents = server.pop_response.response.contents.value
+      assert_match("try_convert(object)", contents)
+      assert_match("(+2 overloads)", contents)
+    end
+  end
+
   def test_hover_for_singleton_methods
     source = <<~RUBY
       class Foo