Fix Unicode offsets in completion replacement ranges

lib/ruby_lsp/listeners/completion.rb

@@ -50,14 +50,15 @@ class Completion
         "__LINE__",
       ].freeze
 
-      #: (ResponseBuilders::CollectionResponseBuilder[Interface::CompletionItem] response_builder, GlobalState global_state, NodeContext node_context, SorbetLevel sorbet_level, Prism::Dispatcher dispatcher, URI::Generic uri, String? trigger_character) -> void
+      #: (ResponseBuilders::CollectionResponseBuilder[Interface::CompletionItem] response_builder, GlobalState global_state, NodeContext node_context, SorbetLevel sorbet_level, Prism::Dispatcher dispatcher, URI::Generic uri, (^(Integer arg0) -> Integer | Prism::CodeUnitsCache) code_units_cache, String? trigger_character) -> void
       def initialize( # rubocop:disable Metrics/ParameterLists
         response_builder,
         global_state,
         node_context,
         sorbet_level,
         dispatcher,
         uri,
+        code_units_cache,
         trigger_character
       )
         @response_builder = response_builder
@@ -67,6 +68,7 @@ def initialize( # rubocop:disable Metrics/ParameterLists
         @node_context = node_context
         @sorbet_level = sorbet_level
         @uri = uri
+        @code_units_cache = code_units_cache
         @trigger_character = trigger_character
 
         dispatcher.register(
@@ -105,7 +107,7 @@ def on_constant_read_node_enter(node)
         name = RubyIndexer::Index.constant_name(node)
         return if name.nil?
 
-        range = range_from_location(node.location)
+        range = range_from_prism_location(node.location)
         candidates = @index.constant_completion_candidates(name, @node_context.nesting)
         candidates.each do |entries|
           complete_name = entries.first #: as !nil
@@ -136,7 +138,7 @@ def on_constant_path_node_enter(node)
         end
         return if name.nil?
 
-        constant_path_completion(name, range_from_location(node.location))
+        constant_path_completion(name, range_from_prism_location(node.location))
       end
 
       #: (Prism::CallNode node) -> void
@@ -161,8 +163,14 @@ def on_call_node_enter(node)
               constant_path_completion(
                 "#{name}::",
                 Interface::Range.new(
-                  start: Interface::Position.new(line: start_loc.start_line - 1, character: start_loc.start_column),
-                  end: Interface::Position.new(line: end_loc.end_line - 1, character: end_loc.end_column),
+                  start: Interface::Position.new(
+                    line: start_loc.start_line - 1,
+                    character: start_loc.cached_start_code_units_column(@code_units_cache),
+                  ),
+                  end: Interface::Position.new(
+                    line: end_loc.end_line - 1,
+                    character: end_loc.cached_end_code_units_column(@code_units_cache),
+                  ),
                 ),
               )
               return
@@ -275,6 +283,20 @@ def on_class_variable_write_node_enter(node)
 
       private
 
+      #: (Prism::Location location) -> Interface::Range
+      def range_from_prism_location(location)
+        Interface::Range.new(
+          start: Interface::Position.new(
+            line: location.start_line - 1,
+            character: location.cached_start_code_units_column(@code_units_cache),
+          ),
+          end: Interface::Position.new(
+            line: location.end_line - 1,
+            character: location.cached_end_code_units_column(@code_units_cache),
+          ),
+        )
+      end
+
       #: (String name, Interface::Range range) -> void
       def constant_path_completion(name, range)
         top_level_reference = if name.start_with?("::")
@@ -338,7 +360,7 @@ def handle_global_variable_completion(name, location)
 
         return if candidates.none?
 
-        range = range_from_location(location)
+        range = range_from_prism_location(location)
 
         candidates.flatten.uniq(&:name).each do |entry|
           entry_name = entry.name
@@ -360,7 +382,7 @@ def handle_class_variable_completion(name, location)
         type = @type_inferrer.infer_receiver_type(@node_context)
         return unless type
 
-        range = range_from_location(location)
+        range = range_from_prism_location(location)
 
         @index.class_variable_completion_candidates(name, type.name).each do |entry|
           variable_name = entry.name
@@ -395,7 +417,7 @@ def handle_instance_variable_completion(name, location)
         type = @type_inferrer.infer_receiver_type(@node_context)
         return unless type
 
-        range = range_from_location(location)
+        range = range_from_prism_location(location)
         @index.instance_variable_completion_candidates(name, type.name).each do |entry|
           variable_name = entry.name
 
@@ -495,16 +517,16 @@ def complete_methods(node, name)
         method_name = @trigger_character == "." ? nil : name
 
         range = if method_name
-          range_from_location(
-            node.message_loc, #: as !nil
-          )
+          location = node.message_loc #: as !nil
+          range_from_prism_location(location)
         else
           loc = node.call_operator_loc
 
           if loc
+            character = loc.cached_start_code_units_column(@code_units_cache) + 1
             Interface::Range.new(
-              start: Interface::Position.new(line: loc.start_line - 1, character: loc.start_column + 1),
-              end: Interface::Position.new(line: loc.start_line - 1, character: loc.start_column + 1),
+              start: Interface::Position.new(line: loc.start_line - 1, character: character),
+              end: Interface::Position.new(line: loc.start_line - 1, character: character),
             )
           end
         end
@@ -550,7 +572,7 @@ def complete_methods(node, name)
 
       #: (Prism::CallNode node, String name) -> void
       def add_local_completions(node, name)
-        range = range_from_location(
+        range = range_from_prism_location(
           node.message_loc, #: as !nil
         )
 
@@ -572,7 +594,7 @@ def add_local_completions(node, name)
 
       #: (Prism::CallNode node, String name) -> void
       def add_keyword_completions(node, name)
-        range = range_from_location(
+        range = range_from_prism_location(
           node.message_loc, #: as !nil
         )
 
@@ -598,7 +620,7 @@ def build_completion(label, node)
         Interface::CompletionItem.new(
           label: label,
           text_edit: Interface::TextEdit.new(
-            range: range_from_location(loc),
+            range: range_from_prism_location(loc),
             new_text: label,
           ),
           kind: Constant::CompletionItemKind::FILE,

lib/ruby_lsp/requests/completion.rb

@@ -70,6 +70,7 @@ def initialize(document, global_state, params, sorbet_level, dispatcher)
           sorbet_level,
           dispatcher,
           document.uri,
+          document.code_units_cache,
           params.dig(:context, :triggerCharacter),
         )
 

test/requests/completion_test.rb

@@ -1535,6 +1535,29 @@ def do_something(abc1, abc2, abc3)
     end
   end
 
+  def test_completion_for_locals_with_unicode_before_cursor
+    source = +<<~'RUBY'
+      test = "moo"
+      "🐮 says #{te}"
+    RUBY
+
+    with_server(source, stub_no_typechecker: true) do |server, uri|
+      server.process_message(id: 1, method: "textDocument/completion", params: {
+        textDocument: { uri: uri },
+        position: { line: 1, character: 13 },
+      })
+
+      result = server.pop_response.response
+      item = result.find { |completion| completion.label == "test" } #: as !nil
+
+      assert_equal("test", item.text_edit.new_text)
+      assert_equal(
+        { start: { line: 1, character: 11 }, end: { line: 1, character: 13 } },
+        item.text_edit.range.to_hash.transform_values(&:to_hash),
+      )
+    end
+  end
+
   def test_completion_for_locals_only_happens_when_there_is_no_receiver
     source = +<<~RUBY
       class Child