Add alternate links to ActivityPub resources from HTML/HEAD variants (#4586)

3 files changed, 20 insertions, 2 deletions

diff --git a/app/controllers/concerns/account_controller_concern.rb b/app/controllers/concerns/account_controller_concern.rb
index d36fc8c93..5b9981aa2 100644
--- a/app/controllers/concerns/account_controller_concern.rb
+++ b/app/controllers/concerns/account_controller_concern.rb
@@ -23,6 +23,7 @@ module AccountControllerConcern
       [
         webfinger_account_link,
         atom_account_url_link,
+        actor_url_link,
       ]
     )
   end
@@ -41,6 +42,13 @@ module AccountControllerConcern
     ]
   end
 
+  def actor_url_link
+    [
+      ActivityPub::TagManager.instance.uri_for(@account),
+      [%w(rel alternate), %w(type application/activity+json)],
+    ]
+  end
+
   def webfinger_account_url
     webfinger_url(resource: @account.to_webfinger_s)
   end
diff --git a/app/controllers/statuses_controller.rb b/app/controllers/statuses_controller.rb
index 8e0ce0ec3..0cce2ba23 100644
--- a/app/controllers/statuses_controller.rb
+++ b/app/controllers/statuses_controller.rb
@@ -36,7 +36,12 @@ class StatusesController < ApplicationController
   end
 
   def set_link_headers
-    response.headers['Link'] = LinkHeader.new([[account_stream_entry_url(@account, @status.stream_entry, format: 'atom'), [%w(rel alternate), %w(type application/atom+xml)]]])
+    response.headers['Link'] = LinkHeader.new(
+      [
+        [account_stream_entry_url(@account, @status.stream_entry, format: 'atom'), [%w(rel alternate), %w(type application/atom+xml)]],
+        [ActivityPub::TagManager.instance.uri_for(@status), [%w(rel alternate), %w(type application/activity+json)]],
+      ]
+    )
   end
 
   def set_status
diff --git a/app/controllers/stream_entries_controller.rb b/app/controllers/stream_entries_controller.rb
index 3eb91d830..ccb15495e 100644
--- a/app/controllers/stream_entries_controller.rb
+++ b/app/controllers/stream_entries_controller.rb
@@ -38,7 +38,12 @@ class StreamEntriesController < ApplicationController
   end
 
   def set_link_headers
-    response.headers['Link'] = LinkHeader.new([[account_stream_entry_url(@account, @stream_entry, format: 'atom'), [%w(rel alternate), %w(type application/atom+xml)]]])
+    response.headers['Link'] = LinkHeader.new(
+      [
+        [account_stream_entry_url(@account, @stream_entry, format: 'atom'), [%w(rel alternate), %w(type application/atom+xml)]],
+        [ActivityPub::TagManager.instance.uri_for(@stream_entry.activity), [%w(rel alternate), %w(type application/activity+json)]],
+      ]
+    )
   end
 
   def set_stream_entry