Fix for RBS::Types::UntypedFunction

Fix completion of `Thread.new{here}`

.github/workflows/test.yml

@@ -35,7 +35,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rbs: ['latest', '3.4', '3.2', '3.0', '2.7.0']
+        rbs: ['latest', '3.6', '3.4', '3.2', '3.0', '2.7.0']
     env:
       GEMFILE_RBS_VERSION: ${{ matrix.rbs }}
     steps:

lib/repl_type_completor/type_analyzer.rb

@@ -1145,7 +1145,7 @@ def method_call(receiver, method_name, args, kwargs, block, scope, name_match: t
         receiver_vars = receiver.is_a?(Types::InstanceType) ? receiver.params : {}
         free_vars = method.type.free_variables - receiver_vars.keys.to_set
         vars = receiver_vars.merge Types.match_free_variables(free_vars, method_params, given_params)
-        if block && method.block
+        if block && method.block && method.block.type.respond_to?(:required_positionals)
           params_type = method.block.type.required_positionals.map do |func_param|
             Types.from_rbs_type func_param.type, receiver, vars
           end

test/repl_type_completor/test_type_analyze.rb

@@ -13,7 +13,7 @@ def ReplTypeCompletor.handle_exception(e)
       end
       ReplTypeCompletor::Types.load_rbs_builder unless ReplTypeCompletor::Types.rbs_builder
     end
-    
+
     def teardown
       ReplTypeCompletor.singleton_class.remove_method(:handle_exception)
       ReplTypeCompletor.define_singleton_method(:handle_exception, &@handle_exception_method)
@@ -711,5 +711,12 @@ def test_array_aref
       assert_call('[1].[](0).', include: Integer, exclude: [Array, NilClass])
       assert_call('[1].[](0){}.', include: Integer, exclude: [Array, NilClass])
     end
+
+    def test_rbs_untyped_function
+      # Block of Thread#initialize: (*untyped) { (?) -> void } -> void
+      # is RBS::Types::UntypedFunction
+      assert_call('Thread.new{_1.', include: NilClass)
+      assert_call('"a".instance_eval{Thread.new{self.', include: String)
+    end
   end
 end