Fix TwitterCard meta tags

TwitterCard meta tags are supposed to use the attributes "name" and "content".
OpenGraph tags use the attributes "property" and "content".

Twitter itself is smart enough to detect broken meta tags and discover the TwitterCard
using "property" and "content", but other platforms that only implement parsing of TwitterCards
and not OpenGraph may fail to correctly detect the tags as they're under the wrong attributes.

> "Open Graph protocol also specifies the use of property and content attributes for markup while
> Twitter cards use name and content. Twitter’s parser will fall back to using property and content,
> so there is no need to modify existing Open Graph protocol markup if it already exists." [0]

[0] https://developer.twitter.com/en/docs/twitter-for-websites/cards/guides/getting-started

3 files changed, 50 insertions, 50 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a3cff84a1..3d42a4cfe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -59,6 +59,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fixed lowercase HTTP HEAD method in the Media Proxy Preview code
 - Removed useless notification call on Delete activities
 - Improved performance for filtering out deactivated and invisible users
+- TwitterCard meta tags conformance
 
 ### Removed
 - Quack, the logging backend that pushes to Slack channels
diff --git a/lib/pleroma/web/metadata/providers/twitter_card.ex b/lib/pleroma/web/metadata/providers/twitter_card.ex
index bf0a12212..2dac22ee2 100644
--- a/lib/pleroma/web/metadata/providers/twitter_card.ex
+++ b/lib/pleroma/web/metadata/providers/twitter_card.ex
@@ -20,12 +20,12 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCard do
 
     [
       title_tag(user),
-      {:meta, [property: "twitter:description", content: scrubbed_content], []}
+      {:meta, [name: "twitter:description", content: scrubbed_content], []}
     ] ++
       if attachments == [] or Metadata.activity_nsfw?(object) do
         [
           image_tag(user),
-          {:meta, [property: "twitter:card", content: "summary"], []}
+          {:meta, [name: "twitter:card", content: "summary"], []}
         ]
       else
         attachments
@@ -37,20 +37,19 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCard do
     with truncated_bio = Utils.scrub_html_and_truncate(user.bio) do
       [
         title_tag(user),
-        {:meta, [property: "twitter:description", content: truncated_bio], []},
+        {:meta, [name: "twitter:description", content: truncated_bio], []},
         image_tag(user),
-        {:meta, [property: "twitter:card", content: "summary"], []}
+        {:meta, [name: "twitter:card", content: "summary"], []}
       ]
     end
   end
 
   defp title_tag(user) do
-    {:meta, [property: "twitter:title", content: Utils.user_name_string(user)], []}
+    {:meta, [name: "twitter:title", content: Utils.user_name_string(user)], []}
   end
 
   def image_tag(user) do
-    {:meta, [property: "twitter:image", content: MediaProxy.preview_url(User.avatar_url(user))],
-     []}
+    {:meta, [name: "twitter:image", content: MediaProxy.preview_url(User.avatar_url(user))], []}
   end
 
   defp build_attachments(id, %{data: %{"attachment" => attachments}}) do
@@ -60,10 +59,10 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCard do
           case Utils.fetch_media_type(@media_types, url["mediaType"]) do
             "audio" ->
               [
-                {:meta, [property: "twitter:card", content: "player"], []},
-                {:meta, [property: "twitter:player:width", content: "480"], []},
-                {:meta, [property: "twitter:player:height", content: "80"], []},
-                {:meta, [property: "twitter:player", content: player_url(id)], []}
+                {:meta, [name: "twitter:card", content: "player"], []},
+                {:meta, [name: "twitter:player:width", content: "480"], []},
+                {:meta, [name: "twitter:player:height", content: "80"], []},
+                {:meta, [name: "twitter:player", content: player_url(id)], []}
                 | acc
               ]
 
@@ -74,10 +73,10 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCard do
             # workaround.
             "image" ->
               [
-                {:meta, [property: "twitter:card", content: "summary_large_image"], []},
+                {:meta, [name: "twitter:card", content: "summary_large_image"], []},
                 {:meta,
                  [
-                   property: "twitter:player",
+                   name: "twitter:player",
                    content: MediaProxy.url(url["href"])
                  ], []}
                 | acc
@@ -90,14 +89,14 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCard do
               width = url["width"] || 480
 
               [
-                {:meta, [property: "twitter:card", content: "player"], []},
-                {:meta, [property: "twitter:player", content: player_url(id)], []},
-                {:meta, [property: "twitter:player:width", content: "#{width}"], []},
-                {:meta, [property: "twitter:player:height", content: "#{height}"], []},
-                {:meta, [property: "twitter:player:stream", content: MediaProxy.url(url["href"])],
+                {:meta, [name: "twitter:card", content: "player"], []},
+                {:meta, [name: "twitter:player", content: player_url(id)], []},
+                {:meta, [name: "twitter:player:width", content: "#{width}"], []},
+                {:meta, [name: "twitter:player:height", content: "#{height}"], []},
+                {:meta, [name: "twitter:player:stream", content: MediaProxy.url(url["href"])],
                  []},
-                {:meta,
-                 [property: "twitter:player:stream:content_type", content: url["mediaType"]], []}
+                {:meta, [name: "twitter:player:stream:content_type", content: url["mediaType"]],
+                 []}
                 | acc
               ]
 
@@ -123,8 +122,8 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCard do
       !is_nil(url["height"]) && !is_nil(url["width"]) ->
         metadata ++
           [
-            {:meta, [property: "twitter:player:width", content: "#{url["width"]}"], []},
-            {:meta, [property: "twitter:player:height", content: "#{url["height"]}"], []}
+            {:meta, [name: "twitter:player:width", content: "#{url["width"]}"], []},
+            {:meta, [name: "twitter:player:height", content: "#{url["height"]}"], []}
           ]
 
       true ->
diff --git a/test/pleroma/web/metadata/providers/twitter_card_test.exs b/test/pleroma/web/metadata/providers/twitter_card_test.exs
index 1a0cea9ce..be4cfbe7b 100644
--- a/test/pleroma/web/metadata/providers/twitter_card_test.exs
+++ b/test/pleroma/web/metadata/providers/twitter_card_test.exs
@@ -22,10 +22,10 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCardTest do
     res = TwitterCard.build_tags(%{user: user})
 
     assert res == [
-             {:meta, [property: "twitter:title", content: Utils.user_name_string(user)], []},
-             {:meta, [property: "twitter:description", content: "born 19 March 1994"], []},
-             {:meta, [property: "twitter:image", content: avatar_url], []},
-             {:meta, [property: "twitter:card", content: "summary"], []}
+             {:meta, [name: "twitter:title", content: Utils.user_name_string(user)], []},
+             {:meta, [name: "twitter:description", content: "born 19 March 1994"], []},
+             {:meta, [name: "twitter:image", content: avatar_url], []},
+             {:meta, [name: "twitter:card", content: "summary"], []}
            ]
   end
 
@@ -47,11 +47,11 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCardTest do
     result = TwitterCard.build_tags(%{object: note, user: user, activity_id: activity.id})
 
     assert [
-             {:meta, [property: "twitter:title", content: Utils.user_name_string(user)], []},
-             {:meta, [property: "twitter:description", content: "pleroma in a nutshell"], []},
-             {:meta, [property: "twitter:image", content: "http://localhost:4001/images/avi.png"],
+             {:meta, [name: "twitter:title", content: Utils.user_name_string(user)], []},
+             {:meta, [name: "twitter:description", content: "pleroma in a nutshell"], []},
+             {:meta, [name: "twitter:image", content: "http://localhost:4001/images/avi.png"],
               []},
-             {:meta, [property: "twitter:card", content: "summary"], []}
+             {:meta, [name: "twitter:card", content: "summary"], []}
            ] == result
   end
 
@@ -73,15 +73,15 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCardTest do
     result = TwitterCard.build_tags(%{object: note, user: user, activity_id: activity.id})
 
     assert [
-             {:meta, [property: "twitter:title", content: Utils.user_name_string(user)], []},
+             {:meta, [name: "twitter:title", content: Utils.user_name_string(user)], []},
              {:meta,
               [
-                property: "twitter:description",
+                name: "twitter:description",
                 content: "Public service announcement on caffeine consumption"
               ], []},
-             {:meta, [property: "twitter:image", content: "http://localhost:4001/images/avi.png"],
+             {:meta, [name: "twitter:image", content: "http://localhost:4001/images/avi.png"],
               []},
-             {:meta, [property: "twitter:card", content: "summary"], []}
+             {:meta, [name: "twitter:card", content: "summary"], []}
            ] == result
   end
 
@@ -123,11 +123,11 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCardTest do
     result = TwitterCard.build_tags(%{object: note, user: user, activity_id: activity.id})
 
     assert [
-             {:meta, [property: "twitter:title", content: Utils.user_name_string(user)], []},
-             {:meta, [property: "twitter:description", content: "pleroma in a nutshell"], []},
-             {:meta, [property: "twitter:image", content: "http://localhost:4001/images/avi.png"],
+             {:meta, [name: "twitter:title", content: Utils.user_name_string(user)], []},
+             {:meta, [name: "twitter:description", content: "pleroma in a nutshell"], []},
+             {:meta, [name: "twitter:image", content: "http://localhost:4001/images/avi.png"],
               []},
-             {:meta, [property: "twitter:card", content: "summary"], []}
+             {:meta, [name: "twitter:card", content: "summary"], []}
            ] == result
   end
 
@@ -179,26 +179,26 @@ defmodule Pleroma.Web.Metadata.Providers.TwitterCardTest do
     result = TwitterCard.build_tags(%{object: note, user: user, activity_id: activity.id})
 
     assert [
-             {:meta, [property: "twitter:title", content: Utils.user_name_string(user)], []},
-             {:meta, [property: "twitter:description", content: "pleroma in a nutshell"], []},
-             {:meta, [property: "twitter:card", content: "summary_large_image"], []},
-             {:meta, [property: "twitter:player", content: "https://pleroma.gov/tenshi.png"], []},
-             {:meta, [property: "twitter:player:width", content: "1280"], []},
-             {:meta, [property: "twitter:player:height", content: "1024"], []},
-             {:meta, [property: "twitter:card", content: "player"], []},
+             {:meta, [name: "twitter:title", content: Utils.user_name_string(user)], []},
+             {:meta, [name: "twitter:description", content: "pleroma in a nutshell"], []},
+             {:meta, [name: "twitter:card", content: "summary_large_image"], []},
+             {:meta, [name: "twitter:player", content: "https://pleroma.gov/tenshi.png"], []},
+             {:meta, [name: "twitter:player:width", content: "1280"], []},
+             {:meta, [name: "twitter:player:height", content: "1024"], []},
+             {:meta, [name: "twitter:card", content: "player"], []},
              {:meta,
               [
-                property: "twitter:player",
+                name: "twitter:player",
                 content: Router.Helpers.o_status_url(Endpoint, :notice_player, activity.id)
               ], []},
-             {:meta, [property: "twitter:player:width", content: "800"], []},
-             {:meta, [property: "twitter:player:height", content: "600"], []},
+             {:meta, [name: "twitter:player:width", content: "800"], []},
+             {:meta, [name: "twitter:player:height", content: "600"], []},
              {:meta,
               [
-                property: "twitter:player:stream",
+                name: "twitter:player:stream",
                 content: "https://pleroma.gov/about/juche.webm"
               ], []},
-             {:meta, [property: "twitter:player:stream:content_type", content: "video/webm"], []}
+             {:meta, [name: "twitter:player:stream:content_type", content: "video/webm"], []}
            ] == result
   end
 end