add class-level body predicates to Net::HTTPRequest

lib/net/http/request.rb

@@ -86,4 +86,22 @@ def initialize(path, initheader = nil)
           self.class::RESPONSE_HAS_BODY,
           path, initheader
   end
+
+  # Returns whether the request may have a body:
+  #
+  #   Net::HTTP::Post.request_body_permitted? # => true
+  #   Net::HTTP::Get.request_body_permitted?  # => false
+  #
+  def self.request_body_permitted?
+    self::REQUEST_HAS_BODY
+  end
+
+  # Returns whether the response may have a body:
+  #
+  #   Net::HTTP::Post.response_body_permitted? # => true
+  #   Net::HTTP::Head.response_body_permitted? # => false
+  #
+  def self.response_body_permitted?
+    self::RESPONSE_HAS_BODY
+  end
 end

sig/net-http.rbs

@@ -3312,6 +3312,28 @@ module Net
     #
     def initialize: (String path, ?headers initheader) -> void
                   | (URI::Generic uri, ?headers initheader) -> void
+
+    # <!--
+    #   rdoc-file=lib/net/http/request.rb
+    #   - request_body_permitted?()
+    # -->
+    # Returns whether the request may have a body:
+    #
+    #     Net::HTTP::Post.request_body_permitted? # => true
+    #     Net::HTTP::Get.request_body_permitted?  # => false
+    #
+    def self.request_body_permitted?: () -> bool
+
+    # <!--
+    #   rdoc-file=lib/net/http/request.rb
+    #   - response_body_permitted?()
+    # -->
+    # Returns whether the response may have a body:
+    #
+    #     Net::HTTP::Post.response_body_permitted? # => true
+    #     Net::HTTP::Head.response_body_permitted? # => false
+    #
+    def self.response_body_permitted?: () -> bool
   end
 
   # <!-- rdoc-file=lib/net/http/requests.rb -->

test/net/http/test_http_request.rb

@@ -122,4 +122,14 @@ def test_update_uri
     assert_equal "[2001:db8::1]", req.uri.host
     assert_equal 8080, req.uri.port
   end
+
+  def test_request_body_permitted?
+    assert_predicate Net::HTTP::Post, :request_body_permitted?
+    assert_not_predicate Net::HTTP::Get, :request_body_permitted?
+  end
+
+  def test_response_body_permitted?
+    assert_predicate Net::HTTP::Post, :response_body_permitted?
+    assert_not_predicate Net::HTTP::Head, :response_body_permitted?
+  end
 end

test_sig/test_net_http.rb

@@ -550,6 +550,23 @@ def test_iteration_on_headers
   end
 end
 
+class TestSingletonNetHTTPRequest < Test::Unit::TestCase
+  include RBS::UnitTest::TypeAssertions
+
+  library "net-http"
+  testing "singleton(::Net::HTTPRequest)"
+
+  def test_request_body_permitted?
+    assert_send_type "() -> bool",
+                     Net::HTTP::Post, :request_body_permitted?
+  end
+
+  def test_response_body_permitted?
+    assert_send_type "() -> bool",
+                     Net::HTTP::Post, :response_body_permitted?
+  end
+end
+
 class TestSingletonNetHTTPResponse < Test::Unit::TestCase
   include RBS::UnitTest::TypeAssertions