actionpack: stop typing the abstract render_to_body as nil

gems/actionpack/7.2/_test/test.rb

@@ -82,3 +82,12 @@ def matches?(request)
   mount Rack::Head.new(->(_env) { [200, { "content-type" => "text/plain" }, ["OK"]] }), at: "/head", as: :head
   with_default_scope(module: "v1") { get "ping", to: "ping#show" }.has_named_route?(:ping)
 end
+
+# render_to_body returns what the including class renders, so it can be truthy
+class BodyRenderer
+  include AbstractController::Rendering
+
+  def show
+    render_to_body(template: "show") ? "rendered" : "empty"
+  end
+end

gems/actionpack/7.2/_test/test.rbs

@@ -14,3 +14,9 @@ end
 class AdminConstraint
   def matches?: (ActionDispatch::Request request) -> bool
 end
+
+class BodyRenderer
+  include AbstractController::Rendering
+
+  def show: () -> String
+end

gems/actionpack/7.2/actioncontroller.rbs

@@ -291,6 +291,9 @@ end
 
 module AbstractController
   module Rendering
+    # Performs the actual template rendering.
+    def render_to_body: (?::Hash[untyped, untyped] options) -> untyped
+
     def render_to_string: (*untyped args) ?{ () -> untyped } -> ::String
   end
 end

gems/actionpack/7.2/actionpack-generated.rbs

@@ -511,9 +511,6 @@ module AbstractController
     # sticks the result in <tt>self.response_body</tt>.
     def render: (*untyped args) { () -> untyped } -> untyped
 
-    # Performs the actual template rendering.
-    def render_to_body: (?::Hash[untyped, untyped] options) -> nil
-
     # Returns Content-Type of rendered content.
     def rendered_format: () -> untyped
 

gems/actionpack/8.1/_test/test.rb

@@ -168,3 +168,12 @@ def matches?(request)
   mount Rack::Head.new(->(_env) { [200, { "content-type" => "text/plain" }, ["OK"]] }), at: "/head", as: :head
   with_default_scope(module: "v1") { get "ping", to: "ping#show" }.has_named_route?(:ping)
 end
+
+# render_to_body returns what the including class renders, so it can be truthy
+class BodyRenderer
+  include AbstractController::Rendering
+
+  def show
+    render_to_body(template: "show") ? "rendered" : "empty"
+  end
+end

gems/actionpack/8.1/_test/test.rbs

@@ -28,3 +28,9 @@ end
 class AdminConstraint
   def matches?: (ActionDispatch::Request request) -> bool
 end
+
+class BodyRenderer
+  include AbstractController::Rendering
+
+  def show: () -> String
+end

gems/actionpack/8.1/actioncontroller.rbs

@@ -317,6 +317,9 @@ end
 
 module AbstractController
   module Rendering
+    # Performs the actual template rendering.
+    def render_to_body: (?::Hash[untyped, untyped] options) -> untyped
+
     def render_to_string: (*untyped args) ?{ () -> untyped } -> ::String
   end
 end

gems/actionpack/8.1/actionpack-generated.rbs

@@ -527,9 +527,6 @@ module AbstractController
     # Supported options depend on the underlying `render_to_body` implementation.
     def render: (*untyped args) ?{ (?) -> untyped } -> untyped
 
-    # Performs the actual template rendering.
-    def render_to_body: (?::Hash[untyped, untyped] options) -> nil
-
     # Returns `Content-Type` of rendered content.
     def rendered_format: () -> untyped