Return semantic tokens for local vars shadowed by parameters (#2509)

lib/ruby_lsp/listeners/semantic_highlighting.rb

@@ -41,6 +41,7 @@ def initialize(dispatcher, response_builder)
           :on_block_node_leave,
           :on_self_node_enter,
           :on_module_node_enter,
+          :on_local_variable_write_node_enter,
           :on_local_variable_read_node_enter,
           :on_block_parameter_node_enter,
           :on_required_keyword_parameter_node_enter,
@@ -49,6 +50,9 @@ def initialize(dispatcher, response_builder)
           :on_optional_parameter_node_enter,
           :on_required_parameter_node_enter,
           :on_rest_parameter_node_enter,
+          :on_local_variable_and_write_node_enter,
+          :on_local_variable_operator_write_node_enter,
+          :on_local_variable_or_write_node_enter,
           :on_local_variable_target_node_enter,
           :on_block_local_variable_node_enter,
           :on_match_write_node_enter,
@@ -164,6 +168,12 @@ def on_self_node_enter(node)
         @response_builder.add_token(node.location, :variable, [:default_library])
       end
 
+      sig { params(node: Prism::LocalVariableWriteNode).void }
+      def on_local_variable_write_node_enter(node)
+        type = @current_scope.type_for(node.name)
+        @response_builder.add_token(node.name_loc, type) if type == :parameter
+      end
+
       sig { params(node: Prism::LocalVariableReadNode).void }
       def on_local_variable_read_node_enter(node)
         return if @inside_implicit_node
@@ -177,6 +187,24 @@ def on_local_variable_read_node_enter(node)
         @response_builder.add_token(node.location, @current_scope.type_for(node.name))
       end
 
+      sig { params(node: Prism::LocalVariableAndWriteNode).void }
+      def on_local_variable_and_write_node_enter(node)
+        type = @current_scope.type_for(node.name)
+        @response_builder.add_token(node.name_loc, type) if type == :parameter
+      end
+
+      sig { params(node: Prism::LocalVariableOperatorWriteNode).void }
+      def on_local_variable_operator_write_node_enter(node)
+        type = @current_scope.type_for(node.name)
+        @response_builder.add_token(node.name_loc, type) if type == :parameter
+      end
+
+      sig { params(node: Prism::LocalVariableOrWriteNode).void }
+      def on_local_variable_or_write_node_enter(node)
+        type = @current_scope.type_for(node.name)
+        @response_builder.add_token(node.name_loc, type) if type == :parameter
+      end
+
       sig { params(node: Prism::LocalVariableTargetNode).void }
       def on_local_variable_target_node_enter(node)
         # If we're inside a regex capture, Prism will add LocalVariableTarget nodes for each captured variable.

test/expectations/semantic_highlighting/vars_shadowed_by_params.exp.json

@@ -0,0 +1,32 @@
+{
+    "result": [
+        {
+            "delta_line": 1,
+            "delta_start_char": 2,
+            "length": 1,
+            "token_type": 7,
+            "token_modifiers": 0
+        },
+        {
+            "delta_line": 1,
+            "delta_start_char": 2,
+            "length": 1,
+            "token_type": 7,
+            "token_modifiers": 0
+        },
+        {
+            "delta_line": 1,
+            "delta_start_char": 2,
+            "length": 1,
+            "token_type": 7,
+            "token_modifiers": 0
+        },
+        {
+            "delta_line": 1,
+            "delta_start_char": 2,
+            "length": 1,
+            "token_type": 7,
+            "token_modifiers": 0
+        }
+    ]
+}

test/fixtures/vars_shadowed_by_params.rb

@@ -0,0 +1,6 @@
+def foo(a, b, c, d)
+  a = 123
+  b &&= 123
+  c += 123
+  d ||= 123
+end