Merge pull request #532 from ruby/curry

Generate hook method with required args

lib/rbs/test/hook.rb

@@ -67,12 +67,19 @@ def self.setup_alias_method_chain(klass, target, random:)
         end
       end
 
-      def self.hook_method_source(prefix, method_name, key, random:)
+      def self.hook_method_source(prefix, method_name, key, random:, params:)
         with_name, without_name = alias_names(method_name, random)
         full_method_name = "#{prefix}#{method_name}"
 
+        param_source = params.take_while {|param| param[0] == :req }.map(&:last) + ["*rest_args_#{random}"]
+
+        RBS.logger.debug {
+          "Generating method definition: def #{with_name}(#{param_source.join(", ")}, &block) ..."
+        }
+
         [__LINE__ + 1, <<RUBY]
-def #{with_name}(*args, &block)
+def #{with_name}(#{param_source.join(", ")}, &block)
+  args = [#{param_source.join(", ")}]
   ::RBS.logger.debug { "#{full_method_name} with arguments: [" + args.map(&:inspect).join(", ") + "]" }
 
   begin
@@ -171,15 +178,17 @@ def #{with_name}(*args, &block)
 
       def self.hook_instance_method(klass, method, key:)
         random = SecureRandom.hex(4)
-        line, source = hook_method_source("#{klass}#", method, key, random: random)
+        params = klass.instance_method(method).parameters
+        line, source = hook_method_source("#{klass}#", method, key, random: random, params: params)
 
         klass.module_eval(source, __FILE__, line)
         setup_alias_method_chain klass, method, random: random
       end
 
       def self.hook_singleton_method(klass, method, key:)
         random = SecureRandom.hex(4)
-        line, source = hook_method_source("#{klass}.",method, key, random: random)
+        params = klass.method(method).parameters
+        line, source = hook_method_source("#{klass}.",method, key, random: random, params: params)
 
         klass.singleton_class.module_eval(source, __FILE__, line)
         setup_alias_method_chain klass.singleton_class, method, random: random

test/rbs/test/runtime_test_test.rb

@@ -267,6 +267,40 @@ def call(val, &block)
 RUBY
   end
 
+  def test_method_curry
+    assert_test_success(other_env: { 'RBS_TEST_TARGET' => "A" }, rbs_content: <<RBS, ruby_content: <<'RUBY')
+class A
+  def on_object: (Integer, String) -> void
+end
+RBS
+class A
+  def on_object(x, y)
+    pp(x: x, y: y)
+  end
+end
+
+STDOUT.puts A.new.method(:on_object).curry[1][""]
+RUBY
+  end
+
+  def test_missing_required_args
+    output = refute_test_success(ruby_content: <<RUBY, rbs_content: <<RBS)
+class Hello
+  def world(x)
+  end
+end
+
+Hello.new.world()
+RUBY
+class Hello
+  def world: (Integer) -> void
+end
+RBS
+
+    # Ruby's standard ArgumentError is raised if required argument is not given.
+    assert_match(/\(ArgumentError\)/, output)
+  end
+
   def test_method_callbacks
     assert_test_success(other_env: { 'RBS_TEST_TARGET' => "Callbacks" }, rbs_content: <<RBS, ruby_content: <<'RUBY')
 module Callbacks