Give html: rendering param the same treatment as content: (#362)

broadcast_action_to accepts a content: argument to set the
turbo-stream template content directly, bypassing any rendering. Other
params, like partial: or locals:  are delegated to render.

Since the arguments are passed directly to render, you might expect you can
also use html: as an argument here. However, there's a catch: when using
a queue system to broadcast the action later, the html_safe flag of
the html param might be lost in the serialization process. Specifically,
the flag remains with queue backends that work in process (like `inline` or `async`)
but it's lost in other that serialize the payload to JSON (like `resque`
or `sidekiq`).

The resulting effect is that the broadcast action works fine in
development, but then fails when it's deployed to a production system.

This problem seems to have tripped a few people:

#284

Treating html: the same as content: solves the issue.

Author: afcapel

app/channels/turbo/streams/broadcasts.rb

@@ -35,7 +35,7 @@ def broadcast_prepend_to(*streamables, **opts)
 
   def broadcast_action_to(*streamables, action:, target: nil, targets: nil, **rendering)
     broadcast_stream_to(*streamables, content: turbo_stream_action_tag(action, target: target, targets: targets, template:
-      rendering.delete(:content) || (rendering.any? ? render_format(:html, **rendering) : nil)
+      rendering.delete(:content) || rendering.delete(:html) || (rendering.any? ? render_format(:html, **rendering) : nil)
     ))
   end
 

test/streams/streams_channel_test.rb

@@ -89,6 +89,14 @@ class Turbo::StreamsChannelTest < ActionCable::Channel::TestCase
     assert_broadcast_on "stream", turbo_stream_action_tag("prepend", targets: ".message", template: render(options)) do
       Turbo::StreamsChannel.broadcast_action_to "stream", action: "prepend", targets: ".message", **options
     end
+
+    assert_broadcast_on "stream", turbo_stream_action_tag("prepend", targets: ".message", template: "<span>test</span>") do
+      Turbo::StreamsChannel.broadcast_action_to "stream", action: "prepend", targets: ".message", content: "<span>test</span>"
+    end
+
+    assert_broadcast_on "stream", turbo_stream_action_tag("prepend", targets: ".message", template: "<span>test</span>") do
+      Turbo::StreamsChannel.broadcast_action_to "stream", action: "prepend", targets: ".message", html: "<span>test</span>"
+    end
   end
 
   test "broadcasting replace later" do